diff --git a/hecl/extern/boo b/hecl/extern/boo
index 136e43dcf..02c1004d6 160000
--- a/hecl/extern/boo
+++ b/hecl/extern/boo
@@ -1 +1 @@
-Subproject commit 136e43dcfef11268a0fcb4e6b10c7febf1e64262
+Subproject commit 02c1004d673989c900b09c3e8a01132c886812fb
diff --git a/hecl/lib/Backend/GLSL.cpp b/hecl/lib/Backend/GLSL.cpp
index 532e3ecc7..f3d3e160b 100644
--- a/hecl/lib/Backend/GLSL.cpp
+++ b/hecl/lib/Backend/GLSL.cpp
@@ -171,7 +171,7 @@ std::string GLSL::makeFrag(const char* glslVer,
         lightingSrc = lighting.m_source;
 
     std::string texMapDecl;
-    for (int i=0 ; i<m_texMapEnd ; ++i)
+    for (unsigned i=0 ; i<m_texMapEnd ; ++i)
         texMapDecl += hecl::Format("TBINDING%u uniform sampler2D tex%u;\n", i, i);
 
     std::string retval = std::string(glslVer) + "\n" BOO_GLSL_BINDING_HEAD +
@@ -221,7 +221,7 @@ std::string GLSL::makeFrag(const char* glslVer,
         postEntry = post.m_entry;
 
     std::string texMapDecl;
-    for (int i=0 ; i<m_texMapEnd ; ++i)
+    for (unsigned i=0 ; i<m_texMapEnd ; ++i)
         texMapDecl += hecl::Format("TBINDING%u uniform sampler2D tex%u;\n", i, i);
 
     std::string retval = std::string(glslVer) + "\n" BOO_GLSL_BINDING_HEAD +