diff --git a/libraries/gpu/src/gpu/Texture.h b/libraries/gpu/src/gpu/Texture.h
index 502ad33143..9b23b4e695 100755
--- a/libraries/gpu/src/gpu/Texture.h
+++ b/libraries/gpu/src/gpu/Texture.h
@@ -34,7 +34,9 @@ namespace ktx {
 
 namespace gpu {
 
-extern const std::string SOURCE_HASH_KEY;
+
+const std::string SOURCE_HASH_KEY { "hifi.sourceHash" };
+
 const uint8 SOURCE_HASH_BYTES = 16;
 
 // THe spherical harmonics is a nice tool for cubemap, so if required, the irradiance SH can be automatically generated
diff --git a/libraries/ktx/src/ktx/KTX.h b/libraries/ktx/src/ktx/KTX.h
index 42ff4644ca..e8fa019a07 100644
--- a/libraries/ktx/src/ktx/KTX.h
+++ b/libraries/ktx/src/ktx/KTX.h
@@ -70,10 +70,9 @@ end
 
 
 namespace ktx {
-    const std::string HIFI_MIN_POPULATED_MIP_KEY = "hifi.minMip";
-
-
     const uint32_t PACKING_SIZE { sizeof(uint32_t) };
+    const std::string HIFI_MIN_POPULATED_MIP_KEY{ "hifi.minMip" };
+
     using Byte = uint8_t;
 
     enum class GLType : uint32_t {