diff --git a/build/moz.configure/lto-pgo.configure b/build/moz.configure/lto-pgo.configure
--- a/build/moz.configure/lto-pgo.configure
+++ b/build/moz.configure/lto-pgo.configure
@@ -224,17 +224,20 @@ def lto(value, c_compiler, ld64_known_go
             #
             # https://github.com/llvm/llvm-project/blob/e7694f34ab6a12b8bb480cbfcb396d0a64fe965f/llvm/lib/Target/X86/X86.td#L1165-L1187
             if target.cpu == 'x86_64':
                 ldflags.append('-mllvm:-mcpu=x86-64')
             # We do not need special flags for arm64.  Hooray for fixed-length
             # instruction sets.
         else:
             num_cores = multiprocessing.cpu_count()
-            cflags.append("-flto")
+            if len(value) and value[0].lower() == 'full':
+                cflags.append("-flto")
+            else:
+                cflags.append("-flto=thin")
             cflags.append("-flifetime-dse=1")
 
             ldflags.append("-flto=%s" % num_cores)
             ldflags.append("-flifetime-dse=1")
 
         # Tell LTO not to inline functions above a certain size, to mitigate
         # binary size growth while still getting good performance.
         # (For hot functions, PGO will put a multiplier on this limit.)