diff --git a/minimal_heap.h b/minimal_heap.h
index c8a04a4..d30da63 100644
--- a/minimal_heap.h
+++ b/minimal_heap.h
@@ -25,7 +25,7 @@
 typedef uintptr_t MIHP_HeapOpaque;
 
 typedef void*(MIHP_PlatformRequestMemoryFn)(MIHP_HeapOpaque heap, size_t minRequestedSize, size_t* outActualSize);
-typedef bool (MIHP_PlatformFreeMemoryFn)(MIHP_HeapOpaque heap, void* Ptr, size_t actualSize);
+typedef bool (MIHP_PlatformFreeMemoryFn)(MIHP_HeapOpaque heap, void* ptr, size_t actualSize);
 
 typedef enum _MIHP_HeapCorruptionError
 {
diff --git a/minimal_heap_test.vcxproj b/minimal_heap_test.vcxproj
index 06693a7..92a73e8 100644
--- a/minimal_heap_test.vcxproj
+++ b/minimal_heap_test.vcxproj
@@ -124,7 +124,7 @@
     </Link>
   </ItemDefinitionGroup>
   <ItemGroup>
-    <ClCompile Include="minimal_heap_test.c" />
+    <ClCompile Include="minimal_heap_test.cpp" />
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="minimal_heap.h" />
diff --git a/minimal_heap_test.vcxproj.filters b/minimal_heap_test.vcxproj.filters
index aad3cae..b1b7f20 100644
--- a/minimal_heap_test.vcxproj.filters
+++ b/minimal_heap_test.vcxproj.filters
@@ -15,7 +15,7 @@
     </Filter>
   </ItemGroup>
   <ItemGroup>
-    <ClCompile Include="minimal_heap_test.c">
+    <ClCompile Include="minimal_heap_test.cpp">
       <Filter>Quelldateien</Filter>
     </ClCompile>
   </ItemGroup>