diff --git a/build/make/gen_msvs_proj.sh b/build/make/gen_msvs_proj.sh
index 660436d..f1cc04e 100755
--- a/build/make/gen_msvs_proj.sh
+++ b/build/make/gen_msvs_proj.sh
@@ -176,7 +176,8 @@
         -*) die_unknown $opt
         ;;
         *)
-            file_list[${#file_list[@]}]="$(fix_path $opt)"
+            # The paths in file_list are fixed outside of the loop.
+            file_list[${#file_list[@]}]="$opt"
             case "$opt" in
                  *.asm) uses_asm=true
                  ;;
@@ -184,6 +185,10 @@
         ;;
     esac
 done
+
+# Make one call to fix_path for file_list to improve performance.
+fix_file_list
+
 outfile=${outfile:-/dev/stdout}
 guid=${guid:-`generate_uuid`}
 asm_use_custom_step=false
diff --git a/build/make/gen_msvs_vcxproj.sh b/build/make/gen_msvs_vcxproj.sh
index 4ae511e..eee354d 100755
--- a/build/make/gen_msvs_vcxproj.sh
+++ b/build/make/gen_msvs_vcxproj.sh
@@ -198,7 +198,8 @@
         -*) die_unknown $opt
         ;;
         *)
-            file_list[${#file_list[@]}]="$(fix_path $opt)"
+            # The paths in file_list are fixed outside of the loop.
+            file_list[${#file_list[@]}]="$opt"
             case "$opt" in
                  *.asm|*.s) uses_asm=true
                  ;;
@@ -206,6 +207,10 @@
         ;;
     esac
 done
+
+# Make one call to fix_path for file_list to improve performance.
+fix_file_list
+
 outfile=${outfile:-/dev/stdout}
 guid=${guid:-`generate_uuid`}
 asm_use_custom_step=false
diff --git a/build/make/msvs_common.sh b/build/make/msvs_common.sh
index eb2eb7b..90c1488 100644
--- a/build/make/msvs_common.sh
+++ b/build/make/msvs_common.sh
@@ -13,7 +13,7 @@
    && cygpath --help >/dev/null 2>&1; then
     FIXPATH='cygpath -m'
 else
-    FIXPATH='echo'
+    FIXPATH='echo_path'
 fi
 
 die() {
@@ -27,8 +27,23 @@
     exit 1
 }
 
+echo_path() {
+    for path; do
+        echo "$path"
+    done
+}
+
+# Output one, possibly changed based on the system, path per line.
 fix_path() {
-    $FIXPATH "$1"
+    $FIXPATH "$@"
+}
+
+# Corrects the paths in file_list in one pass for efficiency.
+fix_file_list() {
+    # TODO(jzern): this could be more generic and take the array as a param.
+    files=$(fix_path "${file_list[@]}")
+    local IFS=$'\n'
+    file_list=($files)
 }
 
 generate_uuid() {