diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2a887e586..5612aff21 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -366,6 +366,10 @@ if(GIT_EXECUTABLE)
 		set(LWS_BUILD_HASH ${GIT_USER}@${GIT_HOST}-${GIT_HASH})
 	endif()
 
+	if ("${LWS_BUILD_HASH}" STREQUAL "")
+		set(LWS_BUILD_HASH "unknown")
+	endif()
+
 	message("Git commit hash: ${LWS_BUILD_HASH}")
 endif()