diff --git a/cc/cc_test.go b/cc/cc_test.go
index fe54463f1..7534db222 100644
--- a/cc/cc_test.go
+++ b/cc/cc_test.go
@@ -4979,7 +4979,6 @@ func TestIncludeDirectoryOrdering(t *testing.T) {
 
 	conly := []string{"-fPIC", "${config.CommonGlobalConlyflags}"}
 	cppOnly := []string{"-fPIC", "${config.CommonGlobalCppflags}", "${config.DeviceGlobalCppflags}", "${config.ArmCppflags}"}
-	ltoFlags := []string{"-flto=thin", "-fsplit-lto-unit"}
 
 	cflags := []string{"-Werror", "-std=candcpp"}
 	cstd := []string{"-std=gnu17", "-std=conly"}
@@ -5006,17 +5005,17 @@ func TestIncludeDirectoryOrdering(t *testing.T) {
 		{
 			name:     "c",
 			src:      "foo.c",
-			expected: combineSlices(baseExpectedFlags, conly, expectedIncludes, cflags, ltoFlags, cstd, lastIncludes, []string{"${config.NoOverrideGlobalCflags}", "${config.NoOverrideExternalGlobalCflags}"}),
+			expected: combineSlices(baseExpectedFlags, conly, expectedIncludes, cflags, cstd, lastIncludes, []string{"${config.NoOverrideGlobalCflags}", "${config.NoOverrideExternalGlobalCflags}"}),
 		},
 		{
 			name:     "cc",
 			src:      "foo.cc",
-			expected: combineSlices(baseExpectedFlags, cppOnly, expectedIncludes, cflags, ltoFlags, cppstd, lastIncludes, []string{"${config.NoOverrideGlobalCflags}", "${config.NoOverrideExternalGlobalCflags}"}),
+			expected: combineSlices(baseExpectedFlags, cppOnly, expectedIncludes, cflags, cppstd, lastIncludes, []string{"${config.NoOverrideGlobalCflags}", "${config.NoOverrideExternalGlobalCflags}"}),
 		},
 		{
 			name:     "assemble",
 			src:      "foo.s",
-			expected: combineSlices(baseExpectedFlags, []string{"${config.CommonGlobalAsflags}"}, expectedIncludes, ltoFlags, lastIncludes),
+			expected: combineSlices(baseExpectedFlags, []string{"${config.CommonGlobalAsflags}"}, expectedIncludes, lastIncludes),
 		},
 	}
 
diff --git a/cc/lto.go b/cc/lto.go
index e334af9d2..44361db1b 100644
--- a/cc/lto.go
+++ b/cc/lto.go
@@ -74,6 +74,9 @@ func (lto *lto) begin(ctx BaseModuleContext) {
 	} else if ctx.Host() {
 		// Performance and binary size are less important for host binaries.
 		ltoDefault = false
+	} else if ctx.Arch().ArchType.Multilib == "lib32" {
+		// LP32 has many subtle issues and less test coverage.
+		ltoDefault = false
 	}
 
 	// Then, determine the actual LTO mode to use. If different from `ltoDefault`, a variant needs