diff --git a/winpr/include/winpr/environment.h b/winpr/include/winpr/environment.h
index c963f8c9c..cd5c1e66e 100644
--- a/winpr/include/winpr/environment.h
+++ b/winpr/include/winpr/environment.h
@@ -129,15 +129,19 @@ extern "C"
 {
 #endif
 
+	WINPR_ATTR_MALLOC(free, 1)
 	WINPR_API LPCH MergeEnvironmentStrings(PCSTR original, PCSTR merge);
 
 	WINPR_API DWORD GetEnvironmentVariableEBA(LPCSTR envBlock, LPCSTR lpName, LPSTR lpBuffer,
 	                                          DWORD nSize);
 	WINPR_API BOOL SetEnvironmentVariableEBA(LPSTR* envBlock, LPCSTR lpName, LPCSTR lpValue);
 
+	WINPR_ATTR_MALLOC(free, 1)
 	WINPR_API char** EnvironmentBlockToEnvpA(LPCH lpszEnvironmentBlock);
 
 	WINPR_API DWORD GetEnvironmentVariableX(const char* lpName, char* lpBuffer, DWORD nSize);
+
+	WINPR_ATTR_MALLOC(free, 1)
 	WINPR_API char* GetEnvAlloc(LPCSTR lpName);
 
 #ifdef __cplusplus
diff --git a/winpr/include/winpr/path.h b/winpr/include/winpr/path.h
index 4554f49eb..975bfcf44 100644
--- a/winpr/include/winpr/path.h
+++ b/winpr/include/winpr/path.h
@@ -306,10 +306,20 @@ extern "C"
 #endif
 
 	WINPR_API const char* GetKnownPathIdString(int id);
+
+	WINPR_ATTR_MALLOC(free, 1)
 	WINPR_API char* GetKnownPath(int id);
+
+	WINPR_ATTR_MALLOC(free, 1)
 	WINPR_API char* GetKnownSubPath(int id, const char* path);
+
+	WINPR_ATTR_MALLOC(free, 1)
 	WINPR_API char* GetEnvironmentPath(char* name);
+
+	WINPR_ATTR_MALLOC(free, 1)
 	WINPR_API char* GetEnvironmentSubPath(char* name, const char* path);
+
+	WINPR_ATTR_MALLOC(free, 1)
 	WINPR_API char* GetCombinedPath(const char* basePath, const char* subPath);
 
 	WINPR_API BOOL PathMakePathA(LPCSTR path, LPSECURITY_ATTRIBUTES lpAttributes);
diff --git a/winpr/libwinpr/environment/environment.c b/winpr/libwinpr/environment/environment.c
index 191027c48..600b15f20 100644
--- a/winpr/libwinpr/environment/environment.c
+++ b/winpr/libwinpr/environment/environment.c
@@ -301,6 +301,8 @@ BOOL FreeEnvironmentStringsA(LPCH lpszEnvironmentBlock)
 
 BOOL FreeEnvironmentStringsW(LPWCH lpszEnvironmentBlock)
 {
+	free(lpszEnvironmentBlock);
+
 	return TRUE;
 }