diff --git a/cc.sh b/cc.sh
index d0a6f90..5d24bc2 100755
--- a/cc.sh
+++ b/cc.sh
@@ -754,6 +754,15 @@ elif [ "$SPACK_ADD_DEBUG_FLAGS" = "custom" ]; then
     extend flags_list SPACK_DEBUG_FLAGS
 fi
 
+# -ffile-prefix-map=<staging>=. injection for build reproducibility
+case "$mode" in
+    cpp|as|cc|ccld)
+        if [ -n "${SPACK_DEBUG_PREFIX_MAP:-}" ]; then
+            append flags_list "-ffile-prefix-map=${SPACK_DEBUG_PREFIX_MAP}=."
+        fi
+        ;;
+esac
+
 spack_flags_list=""
 
 # Fortran flags come before CPPFLAGS
diff --git a/test/run.sh b/test/run.sh
index 4e64a83..7cb23b0 100755
--- a/test/run.sh
+++ b/test/run.sh
@@ -187,7 +187,7 @@ SPACK_COMPILER_EXTRA_RPATHS SPACK_COMPILER_IMPLICIT_RPATHS
 SPACK_CC_HAS_FRANDOM_SEED SPACK_CXX_HAS_FRANDOM_SEED
 SPACK_FC_HAS_FRANDOM_SEED SPACK_F77_HAS_FRANDOM_SEED
 SPACK_CCACHE_BINARY SPACK_TEST_COMMAND SPACK_ADD_DEBUG_FLAGS SPACK_DEBUG_FLAGS
-SPACK_DEBUG
+SPACK_DEBUG SPACK_DEBUG_PREFIX_MAP
 '
 
 wrapper_environment() {
@@ -1309,6 +1309,52 @@ test_add_debug_flags_validation() {
     unset SPACK_ADD_DEBUG_FLAGS
 }
 
+# ---------------------------------------------------------------------------
+# SPACK_DEBUG_PREFIX_MAP injection
+# ---------------------------------------------------------------------------
+
+test_debug_prefix_map() {
+    wrapper_environment
+
+    # When SPACK_DEBUG_PREFIX_MAP is unset, -ffile-prefix-map must NOT appear.
+    unset SPACK_DEBUG_PREFIX_MAP
+    _out=$(dump_args cc '')
+    expect_not_contains debug_prefix_map_absent "$_out" \
+        '-ffile-prefix-map=/some/stage/path=.'
+
+    # When set, -ffile-prefix-map=<value>=. must appear for C.
+    SPACK_DEBUG_PREFIX_MAP='/some/stage/path'
+    export SPACK_DEBUG_PREFIX_MAP
+    _out=$(dump_args cc '')
+    expect_contains debug_prefix_map_cc "$_out" \
+        '-ffile-prefix-map=/some/stage/path=.'
+
+    # Must appear for C++ wrapper too.
+    _out=$(dump_args c++ '')
+    expect_contains debug_prefix_map_cxx "$_out" \
+        '-ffile-prefix-map=/some/stage/path=.'
+
+    # Must appear for Fortran wrapper too.
+    _out=$(dump_args fc '')
+    expect_contains debug_prefix_map_fc "$_out" \
+        '-ffile-prefix-map=/some/stage/path=.'
+
+    # Must NOT appear in vcheck mode
+    _out=$(dump_args cc '--version')
+    expect_not_contains debug_prefix_map_vcheck "$_out" \
+        '-ffile-prefix-map=/some/stage/path=.'
+
+    # Must NOT appear in ld mode
+    SPACK_DEBUG_PREFIX_MAP='/some/stage/path'
+    export SPACK_DEBUG_PREFIX_MAP
+    _out=$(dump_args ld '')
+    expect_not_contains debug_prefix_map_ld "$_out" \
+        '-ffile-prefix-map=/some/stage/path=.'
+
+    unset SPACK_DEBUG_PREFIX_MAP
+
+}
+
 # ---------------------------------------------------------------------------
 # Runner
 # ---------------------------------------------------------------------------
@@ -1359,6 +1405,7 @@ test_spack_managed_dirs_are_prioritized
 test_frandom_seed_not_added_without_env
 test_frandom_seed_filters_args
 test_add_debug_flags_validation
+test_debug_prefix_map
 '
 
 all_tests="$wrapper_tests $list_ops_tests"