diff --git a/EnvelopeGenerator.sln b/EnvelopeGenerator.sln
index 4c3d37e3..f5725ab8 100644
--- a/EnvelopeGenerator.sln
+++ b/EnvelopeGenerator.sln
@@ -23,7 +23,7 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "EnvelopeGenerator.Generator
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "EnvelopeGenerator.Extensions", "EnvelopeGenerator.Extensions\EnvelopeGenerator.Extensions.csproj", "{47F98812-4280-4D53-B04A-2AAEEA5EBC31}"
 EndProject
-Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Core", "Core", "{614BEFFA-C745-4736-84BD-A64108B4C659}"
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "core", "core", "{9943209E-1744-4944-B1BA-4F87FC1A0EEB}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -76,8 +76,8 @@ Global
 		HideSolutionNode = FALSE
 	EndGlobalSection
 	GlobalSection(NestedProjects) = preSolution
-		{4F32A98D-E6F0-4A09-BD97-1CF26107E837} = {614BEFFA-C745-4736-84BD-A64108B4C659}
-		{5A9984F8-51A2-4558-A415-EC5FEED7CF7D} = {614BEFFA-C745-4736-84BD-A64108B4C659}
+		{4F32A98D-E6F0-4A09-BD97-1CF26107E837} = {9943209E-1744-4944-B1BA-4F87FC1A0EEB}
+		{5A9984F8-51A2-4558-A415-EC5FEED7CF7D} = {9943209E-1744-4944-B1BA-4F87FC1A0EEB}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {73E60370-756D-45AD-A19A-C40A02DACCC7}