diff --git a/pkgs/build-support/setup-hooks/separate-debug-info.sh b/pkgs/build-support/setup-hooks/separate-debug-info.sh
index cf3d7b07a4997..37753d9ce406a 100644
--- a/pkgs/build-support/setup-hooks/separate-debug-info.sh
+++ b/pkgs/build-support/setup-hooks/separate-debug-info.sh
@@ -13,11 +13,7 @@ _separateDebugInfo() {
     # Find executables and dynamic libraries.
     local i magic
     while IFS= read -r -d $'\0' i; do
-        # Skip non-ELF files.
-        exec {fd}< "$i"
-        read -n 4 -u $fd magic
-        exec {fd}<&-
-        if ! [[ "$magic" =~ ELF ]]; then continue; fi
+        if ! isELF "$i"; then continue; fi
 
         # Extract the Build ID. FIXME: there's probably a cleaner way.
         local id="$(readelf -n "$i" | sed 's/.*Build ID: \([0-9a-f]*\).*/\1/; t; d')"
@@ -34,7 +30,7 @@ _separateDebugInfo() {
 
         # Also a create a symlink <original-name>.debug.
         ln -sfn ".build-id/${id:0:2}/${id:2}.debug" "$dst/../$(basename "$i")"
-    done < <(find "$prefix" -type f -a \( -perm /0100 -o -name "*.so" -o -name "*.so.*" \) -print0)
+    done < <(find "$prefix" -type f -print0)
 }
 
 # - We might prefer to compress the debug info during link-time already,
diff --git a/pkgs/development/tools/misc/patchelf/setup-hook.sh b/pkgs/development/tools/misc/patchelf/setup-hook.sh
index a76fbfbd509ca..03b6f362a779e 100644
--- a/pkgs/development/tools/misc/patchelf/setup-hook.sh
+++ b/pkgs/development/tools/misc/patchelf/setup-hook.sh
@@ -5,12 +5,15 @@
 fixupOutputHooks+=('if [ -z "$dontPatchELF" ]; then patchELF "$prefix"; fi')
 
 patchELF() {
-    header "patching ELF executables and libraries in $prefix"
-    if [ -e "$prefix" ]; then
-        find "$prefix" \( \
-            \( -type f -a -name "*.so*" \) -o \
-            \( -type f -a -perm -0100 \) \
-            \) -print -exec patchelf --shrink-rpath '{}' \;
-    fi
+    header "shrinking RPATHs of ELF executables and libraries in $prefix"
+
+    local i
+    while IFS= read -r -d $'\0' i; do
+        if [[ "$i" =~ .build-id ]]; then continue; fi
+        if ! isELF "$i"; then continue; fi
+        echo "shrinking $i"
+        patchelf --shrink-rpath "$i" || true
+    done < <(find "$prefix" -type f -print0)
+
     stopNest
 }
diff --git a/pkgs/stdenv/generic/setup.sh b/pkgs/stdenv/generic/setup.sh
index 7d25472993c59..8081b69bffd37 100644
--- a/pkgs/stdenv/generic/setup.sh
+++ b/pkgs/stdenv/generic/setup.sh
@@ -180,6 +180,17 @@ installBin() {
 }
 
 
+# Return success if the specified file is an ELF object.
+isELF() {
+    local fn="$1"
+    local magic
+    exec {fd}< "$fn"
+    read -n 4 -u $fd magic
+    exec {fd}<&-
+    if [[ "$magic" =~ ELF ]]; then return 0; else return 1; fi
+}
+
+
 ######################################################################
 # Initialisation.