diff --git a/appveyor.yml b/appveyor.yml
index 021df2654..1da32ad4e 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -140,11 +140,21 @@ test_script:
 
     docker exec -e IGNORES="bgw_db_scheduler" -e TEST_TABLESPACE1_PATH="C:\Users\$env:UserName\Documents\tablespace1\" -e TEST_TABLESPACE2_PATH="C:\Users\$env:UserName\Documents\tablespace2\" -e TEST_SPINWAIT_ITERS=10000 -e USER=postgres -it pgregress /bin/bash -c "cd /timescaledb/build && make regresschecklocal"
 
-    #TESTS=drop_extension
+    $TESTS1 = $?
+
+    # TODO can we switch these to file swapping?
+
+    Add-Content "C:\Program Files\postgresql\10\data\postgresql.conf" "timescaledb.license_key = 'E1eyJlbmRfdGltZSI6IjIwMTgtMTAtMDEgKzAwMDAiLCAic3RhcnRfdGltZSI6IjIwMTgtMDktMDEgKzAwMDAiLCAiaWQiOiI0OTBGQjI2MC1BMjkyLTRBRDktOUFBMi0wMzYwODM1NzkxQjgiLCAia2luZCI6InRyaWFsIn0K'"
+
+    Restart-Service postgresql-x64-10
+
+    docker exec -e IGNORES="bgw_db_scheduler" -e TEST_TABLESPACE1_PATH="C:\Users\$env:UserName\Documents\tablespace1\" -e TEST_TABLESPACE2_PATH="C:\Users\$env:UserName\Documents\tablespace2\" -e TEST_SPINWAIT_ITERS=10000 -e USER=postgres -it pgregress /bin/bash -c "cd /timescaledb/build && make regresschecklocal-t"
+
+    if( -not $? -or -not $TESTS1 ) { exit 1 }
 
 on_failure:
   - ps: >-
-      docker exec -it pgregress cat /timescaledb/build/test/regression.diffs /timescaledb/build/test/pgtest/regressions.diffs
+      docker exec -it pgregress cat /timescaledb/build/test/regression.diffs /timescaledb/build/tsl/test/regression.diffs /timescaledb/build/test/pgtest/regressions.diffs
 
       Get-Content -Path "C:\Program Files\postgresql\10\data\pg_log\*"
 
diff --git a/src/chunk.h b/src/chunk.h
index 77b4bb5b5..483a38165 100644
--- a/src/chunk.h
+++ b/src/chunk.h
@@ -75,7 +75,6 @@ extern Chunk *ts_chunk_find(Hyperspace *hs, Point *p);
 extern List *ts_chunk_find_all_oids(Hyperspace *hs, List *dimension_vecs, LOCKMODE lockmode);
 extern Chunk *ts_chunk_copy(Chunk *chunk);
 extern Chunk *ts_chunk_get_by_name_with_memory_context(const char *schema_name, const char *table_name, int16 num_constraints, MemoryContext mctx, bool fail_if_not_found);
-extern Chunk *ts_chunk_get_by_relid(Oid relid, int16 num_constraints, bool fail_if_not_found);
 extern TSDLLEXPORT Chunk *ts_chunk_get_by_id(int32 id, int16 num_constraints, bool fail_if_not_found);
 extern TSDLLEXPORT Chunk *ts_chunk_get_by_relid(Oid relid, int16 num_constraints, bool fail_if_not_found);
 extern bool ts_chunk_exists(const char *schema_name, const char *table_name);
diff --git a/src/cross_module_fn.c b/src/cross_module_fn.c
index 8dbd2b818..1615f2aaa 100644
--- a/src/cross_module_fn.c
+++ b/src/cross_module_fn.c
@@ -63,7 +63,7 @@ ts_reorder_chunk(PG_FUNCTION_ARGS)
  */
 
 static void
-error_no_default_fn()
+error_no_default_fn(void)
 {
 	ereport(ERROR,
 			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -73,7 +73,7 @@ error_no_default_fn()
 }
 
 static bool
-error_no_default_fn_bool_void()
+error_no_default_fn_bool_void(void)
 {
 	error_no_default_fn();
 	return false;
diff --git a/src/dimension.c b/src/dimension.c
index cc0b2308f..09aa4de20 100644
--- a/src/dimension.c
+++ b/src/dimension.c
@@ -115,6 +115,8 @@ dimension_type(TupleInfo *ti)
 		return DIMENSION_TYPE_OPEN;
 
 	elog(ERROR, "invalid partitioning dimension");
+	/* suppress compiler warning on MSVC */
+	return DIMENSION_TYPE_ANY;
 }
 
 static void
diff --git a/src/export.h b/src/export.h
index c719e8a63..851d929fb 100644
--- a/src/export.h
+++ b/src/export.h
@@ -58,7 +58,7 @@
 #endif
 
 #define TS_FUNCTION_INFO_V1(fn) \
-	TSDLLEXPORT Datum fn(PG_FUNCTION_ARGS); \
+	PGDLLEXPORT Datum fn(PG_FUNCTION_ARGS); \
 	PG_FUNCTION_INFO_V1(fn)
 
 #endif							/* TIMESCALEDB_EXPORT_H */
diff --git a/src/hypertable_restrict_info.c b/src/hypertable_restrict_info.c
index db285ffd7..1264739ad 100644
--- a/src/hypertable_restrict_info.c
+++ b/src/hypertable_restrict_info.c
@@ -209,6 +209,8 @@ dimension_restrict_info_add(DimensionRestrictInfo *dri, int strategy, DimensionV
 			return dimension_restrict_info_closed_add((DimensionRestrictInfoClosed *) dri, strategy, values);
 		default:
 			elog(ERROR, "unknown dimension type: %d", dri->dimension->type);
+			/* supress compiler warning on MSVC */
+			return false;
 	}
 }
 
diff --git a/src/license_guc.c b/src/license_guc.c
index 538000205..86c599500 100644
--- a/src/license_guc.c
+++ b/src/license_guc.c
@@ -142,15 +142,45 @@ ts_license_update_check(char **newval, void **extra, GucSource source)
 	Assert(tsl_handle != NULL);
 	Assert(tsl_validate_license_fn != NULL);
 	Assert(tsl_startup_fn != NULL);
+#ifdef WIN32
+
+	/*
+	 * freeing the guc extra causes heap corruption on windows so instead we
+	 * re-parse in the assign hook
+	 */
+	extra = NULL;
+#endif
 
 	module_can_start = DirectFunctionCall2(
 										   tsl_validate_license_fn,
 										   CStringGetDatum(*newval),
-										   PointerGetDatum(extra));
+										   PointerGetDatum(extra)
+		);
 
 	return DatumGetBool(module_can_start);
 }
 
+#ifdef WIN32
+static void *
+revalidate_license(const char *newval)
+{
+	void	   *extra = NULL;
+	void	  **extra_p = &extra;
+
+	Assert(extra == NULL);
+
+	/*
+	 * Due to windows issues we cannot use the extra parameter. Instead
+	 * re-call the validation function, if we reach this point the license
+	 * must be valid so the function cannot fail cannot fail.
+	 */
+	DirectFunctionCall2(tsl_validate_license_fn,
+						CStringGetDatum(newval),
+						PointerGetDatum(extra_p));
+	return extra;
+}
+#endif
+
 /*
  * `ts_license_on_assign`
  * Links the cross-module function pointers.
@@ -161,6 +191,7 @@ ts_license_on_assign(const char *newval, void *extra)
 	if (!can_load)
 		return;
 
+	Assert(newval != NULL);
 	Assert(TS_LICENSE_TYPE_IS_VALID(newval));
 	if (TS_LICENSE_IS_APACHE_ONLY(newval))
 	{
@@ -170,7 +201,14 @@ ts_license_on_assign(const char *newval, void *extra)
 		return;
 	}
 
+	Assert(tsl_handle != NULL);
+	Assert(tsl_startup_fn != NULL);
 	DirectFunctionCall1(tsl_startup_fn, CharGetDatum(0));
+#ifdef WIN32
+	Assert(extra == NULL);
+	extra = revalidate_license(newval);
+#endif
+	Assert(extra != NULL);
 	ts_cm_functions->tsl_license_on_assign(newval, extra);
 }
 
@@ -245,7 +283,7 @@ loading_failed:
 
 /* SQL functions */
 
-Datum
+PGDLLEXPORT Datum
 ts_tsl_loaded(PG_FUNCTION_ARGS)
 {
 	if (TS_CURRENT_LICENSE_IS_APACHE_ONLY())
@@ -254,7 +292,7 @@ ts_tsl_loaded(PG_FUNCTION_ARGS)
 	PG_RETURN_BOOL(ts_cm_functions->check_tsl_loaded());
 }
 
-Datum
+PGDLLEXPORT Datum
 ts_enterprise_enabled(PG_FUNCTION_ARGS)
 {
 	if (TS_CURRENT_LICENSE_IS_APACHE_ONLY())
@@ -264,7 +302,7 @@ ts_enterprise_enabled(PG_FUNCTION_ARGS)
 }
 
 
-Datum
+PGDLLEXPORT Datum
 ts_current_license_key(PG_FUNCTION_ARGS)
 {
 	Assert(ts_guc_license_key != NULL);
@@ -276,7 +314,7 @@ ts_current_license_key(PG_FUNCTION_ARGS)
  * Apache only. This function allows us to bypass the test that usually disables
  * that.
  */
-Datum
+PGDLLEXPORT Datum
 ts_allow_downgrade_to_apache(PG_FUNCTION_ARGS)
 {
 	downgrade_to_apache_enabled = true;
diff --git a/src/utils.c b/src/utils.c
index 3cc19305e..13fea1898 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -194,6 +194,9 @@ ts_interval_from_now_to_internal(Datum interval, Oid type_oid)
 					 ));
 
 	}
+	/* suppress compiler warnings on MSVC */
+	Assert(false);
+	return 0;
 }
 
 /* Returns approximate period in microseconds */
diff --git a/tsl/src/bgw_policy/reorder_api.c b/tsl/src/bgw_policy/reorder_api.c
index d0d642a56..67aa8a8e3 100644
--- a/tsl/src/bgw_policy/reorder_api.c
+++ b/tsl/src/bgw_policy/reorder_api.c
@@ -152,7 +152,12 @@ reorder_remove_policy(PG_FUNCTION_ARGS)
 					 errmsg("cannot remove reorder policy, no such policy exists")));
 		else
 		{
-			ereport(NOTICE, (errmsg("reorder policy does not exist on hypertable \"%s\", skipping", get_rel_name(hypertable_oid))));
+			char	   *hypertable_name = get_rel_name(hypertable_oid);
+
+			if (hypertable_name != NULL)
+				ereport(NOTICE, (errmsg("reorder policy does not exist on hypertable \"%s\", skipping", hypertable_name)));
+			else
+				ereport(NOTICE, (errmsg("reorder policy does not exist on unnamed hypertable, skipping")));
 			PG_RETURN_NULL();
 		}
 	}
diff --git a/tsl/src/gapfill/exec.c b/tsl/src/gapfill/exec.c
index f3d1d67ac..77d827880 100644
--- a/tsl/src/gapfill/exec.c
+++ b/tsl/src/gapfill/exec.c
@@ -86,7 +86,7 @@ gapfill_datum_get_internal(Datum value, Oid type)
 			 * for other datatypes
 			 */
 			Assert(false);
-			break;
+			return 0;
 	}
 }
 
@@ -116,7 +116,7 @@ gapfill_internal_get_datum(int64 value, Oid type)
 			 * for other datatypes
 			 */
 			Assert(false);
-			break;
+			return Int64GetDatum(0);
 	}
 }
 
diff --git a/tsl/src/license.c b/tsl/src/license.c
index a3e89a4ec..6a07cdf30 100644
--- a/tsl/src/license.c
+++ b/tsl/src/license.c
@@ -80,24 +80,32 @@ tsl_license_update_check(PG_FUNCTION_ARGS)
 	bool		license_deserialized;
 	char	   *license_key = NULL;
 	LicenseInfo **guc_extra = NULL;
+	LicenseInfo license_info = {0};
 
 	Assert(!PG_ARGISNULL(0));
 	Assert(!PG_ARGISNULL(1));
 
 	license_key = PG_GETARG_CSTRING(0);
 	guc_extra = (LicenseInfo **) PG_GETARG_POINTER(1);
-	Assert(guc_extra != NULL);
 
-	/*
-	 * According to the postgres guc documentation, string `extra`s MUST be
-	 * allocated with `malloc`. (postgres attempts to `free` unneeded
-	 * guc-extras with the system `free` upon transaction commit, and there's
-	 * no guarantee that any MemoryContext uses the correct allocator.)
-	 */
-	*guc_extra = malloc(sizeof(LicenseInfo));
+	license_deserialized = license_deserialize_enterprise(license_key, &license_info);
+	if (guc_extra != NULL)
+	{
+		/*
+		 * According to the postgres guc documentation, string `extra`s MUST
+		 * be allocated with `malloc`. (postgres attempts to `free` unneeded
+		 * guc-extras with the system `free` upon transaction commit, and
+		 * there's no guarantee that any MemoryContext uses the correct
+		 * allocator.) However, there is a bug in Windows which causes heap
+		 * corruption if we try to do that. Instead we currently rerun this
+		 * function during the assign, with the assumption that since we
+		 * called the function during the check hook it cannot fail now.
+		 */
+		*guc_extra = malloc(sizeof(LicenseInfo));
+		memcpy(*guc_extra, &license_info, sizeof(LicenseInfo));
+	}
 
-	license_deserialized = license_deserialize_enterprise(license_key, *guc_extra);
-	PG_RETURN_BOOL(license_deserialized && validate_license_info(*guc_extra));
+	PG_RETURN_BOOL(license_deserialized && validate_license_info(&license_info));
 }
 
 /*
@@ -106,7 +114,7 @@ tsl_license_update_check(PG_FUNCTION_ARGS)
 static bool
 license_deserialize_enterprise(char *license_key, LicenseInfo *license_out)
 {
-	LicenseInfo license_temp = {};
+	LicenseInfo license_temp = {0};
 	const LicenseInfo *license_info = NULL;
 	size_t		license_key_len = strlen(license_key);
 
diff --git a/tsl/test/expected/tsl_tables.out b/tsl/test/expected/tsl_tables.out
index 1cec289b9..7117ffaa6 100644
--- a/tsl/test/expected/tsl_tables.out
+++ b/tsl/test/expected/tsl_tables.out
@@ -275,7 +275,7 @@ ERROR:  relation "fake_table" does not exist at character 30
 \set ON_ERROR_STOP 0
 -- This should be noop
 select remove_reorder_policy(2, true);
-NOTICE:  reorder policy does not exist on hypertable "(null)", skipping
+NOTICE:  reorder policy does not exist on unnamed hypertable, skipping
  remove_reorder_policy 
 -----------------------
  
diff --git a/tsl/test/postgresql.conf b/tsl/test/postgresql.conf
index 1dcbb1730..18948938a 100644
--- a/tsl/test/postgresql.conf
+++ b/tsl/test/postgresql.conf
@@ -1,4 +1,5 @@
 shared_preload_libraries=timescaledb
 max_worker_processes=16
 timescaledb.telemetry_level=off
+# when changing this, also update the one in appveyor.yml
 timescaledb.license_key='E1eyJlbmRfdGltZSI6IjIwMTgtMTAtMDEgKzAwMDAiLCAic3RhcnRfdGltZSI6IjIwMTgtMDktMDEgKzAwMDAiLCAiaWQiOiI0OTBGQjI2MC1BMjkyLTRBRDktOUFBMi0wMzYwODM1NzkxQjgiLCAia2luZCI6InRyaWFsIn0K'