diff --git a/bp2build/cc_library_conversion_test.go b/bp2build/cc_library_conversion_test.go
index 0a72937..454b153 100644
--- a/bp2build/cc_library_conversion_test.go
+++ b/bp2build/cc_library_conversion_test.go
@@ -311,7 +311,7 @@
         "//build/bazel/platforms/arch:arm64": ["-DHAVE_FAST_FMA=1"],
         "//conditions:default": [],
     }),
-    srcs = ["math/cosf.c"],
+    srcs_c = ["math/cosf.c"],
 )`},
 	})
 }
@@ -618,7 +618,7 @@
 
 func TestCcLibraryCppFlagsGoesIntoCopts(t *testing.T) {
 	runCcLibraryTestCase(t, bp2buildTestCase{
-		description:                        "cc_library cppflags goes into copts",
+		description:                        "cc_library cppflags usage",
 		moduleTypeUnderTest:                "cc_library",
 		moduleTypeUnderTestFactory:         cc.LibraryFactory,
 		moduleTypeUnderTestBp2BuildMutator: cc.CcLibraryBp2Build,
@@ -654,10 +654,12 @@
     name = "a",
     copts = [
         "-Wall",
-        "-fsigned-char",
-        "-pedantic",
         "-Ifoo/bar",
         "-I$(BINDIR)/foo/bar",
+    ],
+    cppflags = [
+        "-fsigned-char",
+        "-pedantic",
     ] + select({
         "//build/bazel/platforms/arch:arm64": ["-DARM64=1"],
         "//conditions:default": [],
diff --git a/bp2build/cc_library_static_conversion_test.go b/bp2build/cc_library_static_conversion_test.go
index 44c6ad4..6c2b317 100644
--- a/bp2build/cc_library_static_conversion_test.go
+++ b/bp2build/cc_library_static_conversion_test.go
@@ -650,7 +650,7 @@
         "-I$(BINDIR)/.",
     ],
     linkstatic = True,
-    srcs = [
+    srcs_c = [
         "common.c",
         "foo-a.c",
     ],
@@ -682,7 +682,7 @@
         "-I$(BINDIR)/.",
     ],
     linkstatic = True,
-    srcs = ["common.c"] + select({
+    srcs_c = ["common.c"] + select({
         "//build/bazel/platforms/arch:arm": ["foo-arm.c"],
         "//conditions:default": [],
     }),
@@ -719,7 +719,7 @@
         "-I$(BINDIR)/.",
     ],
     linkstatic = True,
-    srcs = ["common.c"] + select({
+    srcs_c = ["common.c"] + select({
         "//build/bazel/platforms/arch:arm": ["for-arm.c"],
         "//conditions:default": ["not-for-arm.c"],
     }),
@@ -758,7 +758,7 @@
         "-I$(BINDIR)/.",
     ],
     linkstatic = True,
-    srcs = ["common.c"] + select({
+    srcs_c = ["common.c"] + select({
         "//build/bazel/platforms/arch:arm": [
             "for-arm.c",
             "not-for-x86.c",
@@ -813,7 +813,7 @@
         "-I$(BINDIR)/.",
     ],
     linkstatic = True,
-    srcs = ["common.c"] + select({
+    srcs_c = ["common.c"] + select({
         "//build/bazel/platforms/arch:arm": [
             "for-arm.c",
             "not-for-arm64.c",
@@ -909,7 +909,7 @@
         "-I$(BINDIR)/.",
     ],
     linkstatic = True,
-    srcs = ["common.c"] + select({
+    srcs_c = ["common.c"] + select({
         "//build/bazel/platforms/arch:arm": ["for-lib32.c"],
         "//build/bazel/platforms/arch:x86": ["for-lib32.c"],
         "//conditions:default": ["not-for-lib32.c"],
@@ -948,7 +948,7 @@
         "-I$(BINDIR)/.",
     ],
     linkstatic = True,
-    srcs = ["common.c"] + select({
+    srcs_c = ["common.c"] + select({
         "//build/bazel/platforms/arch:arm": [
             "for-lib32.c",
             "not-for-lib64.c",
@@ -1020,7 +1020,7 @@
         "-I$(BINDIR)/.",
     ],
     linkstatic = True,
-    srcs = ["common.c"] + select({
+    srcs_c = ["common.c"] + select({
         "//build/bazel/platforms/arch:arm": [
             "for-arm.c",
             "for-lib32.c",
@@ -1074,10 +1074,10 @@
 		moduleTypeUnderTestBp2BuildMutator: cc.CcLibraryStaticBp2Build,
 		depsMutators:                       []android.RegisterMutatorFunc{cc.RegisterDepsBp2Build},
 		filesystem: map[string]string{
-			"common.c":             "",
-			"for-x86.c":            "",
-			"not-for-x86.c":        "",
-			"not-for-everything.c": "",
+			"common.cpp":             "",
+			"for-x86.cpp":            "",
+			"not-for-x86.cpp":        "",
+			"not-for-everything.cpp": "",
 			"dep/Android.bp": `
 genrule {
 	name: "generated_src_other_pkg",
@@ -1118,14 +1118,14 @@
 
 cc_library_static {
    name: "foo_static3",
-   srcs: ["common.c", "not-for-*.c"],
-   exclude_srcs: ["not-for-everything.c"],
+   srcs: ["common.cpp", "not-for-*.cpp"],
+   exclude_srcs: ["not-for-everything.cpp"],
    generated_sources: ["generated_src", "generated_src_other_pkg"],
    generated_headers: ["generated_hdr", "generated_hdr_other_pkg"],
    arch: {
        x86: {
-           srcs: ["for-x86.c"],
-           exclude_srcs: ["not-for-x86.c"],
+           srcs: ["for-x86.cpp"],
+           exclude_srcs: ["not-for-x86.cpp"],
            generated_sources: ["generated_src_x86"],
            generated_headers: ["generated_hdr_other_pkg_x86"],
        },
@@ -1144,14 +1144,14 @@
         "//dep:generated_src_other_pkg",
         ":generated_hdr",
         ":generated_src",
-        "common.c",
+        "common.cpp",
     ] + select({
         "//build/bazel/platforms/arch:x86": [
             "//dep:generated_hdr_other_pkg_x86",
             ":generated_src_x86",
-            "for-x86.c",
+            "for-x86.cpp",
         ],
-        "//conditions:default": ["not-for-x86.c"],
+        "//conditions:default": ["not-for-x86.cpp"],
     }),
 )`},
 	})
@@ -1197,7 +1197,7 @@
         "//conditions:default": [],
     }),
     linkstatic = True,
-    srcs = ["common.c"],
+    srcs_c = ["common.c"],
 )`},
 	})
 }