diff --git a/build-toolchain.bash b/build-toolchain.bash
index e9d35dde5c..2673e7c9aa 100755
--- a/build-toolchain.bash
+++ b/build-toolchain.bash
@@ -162,6 +162,18 @@ fi
 
 INTERFACES_DIR="$SRC/InterfacesAndLibraries"
 
+function verifyInterfaceDirNames()
+{
+        printf "Searching for special characters in subdirs of $INTERFACES_DIR"
+        local found=`find "$INTERFACES_DIR" -name ".*" -print `
+        if [ "`echo $found | grep \&`" ]; then
+                echo "\n$found Contained special character &"
+                return 1        # failure
+        else
+                return 0        # success
+        fi
+}
+
 function locateInterfaceThing()
 {
 	local varname=$1
@@ -198,6 +210,15 @@ function explainInterfaces()
 
 echo "Looking for various files in $INTERFACES_DIR/..."
 
+if verifyInterfaceDirNames; then
+        echo "Directory name looks clean"
+else
+        echo "Directory name contained special character & that would break build"
+        echo "Please install the Interfaces and Libraries files in a path under"
+        echo "$INTERFACES_DIR that does not contain the & character"
+        exit 1
+fi
+
 if locateInterfaceThing CONDITIONALMACROS_H ConditionalMacros.h; then
 	CINCLUDES=`dirname "$CONDITIONALMACROS_H"`
 else