diff --git a/src/gen_context.c b/src/gen_context.c
index 48b4f98..05e7dee 100644
--- a/src/gen_context.c
+++ b/src/gen_context.c
@@ -47,8 +47,8 @@ int main(int argc, char **argv) {
         return -1;
     }
 
-    fprintf(fp, "#ifndef _SECP256K1_ECMULT_STATIC_CONTEXT_\n");
-    fprintf(fp, "#define _SECP256K1_ECMULT_STATIC_CONTEXT_\n");
+    fprintf(fp, "#ifndef SECP256K1_ECMULT_STATIC_CONTEXT_H\n");
+    fprintf(fp, "#define SECP256K1_ECMULT_STATIC_CONTEXT_H\n");
     fprintf(fp, "#include \"src/group.h\"\n");
     fprintf(fp, "#define SC SECP256K1_GE_STORAGE_CONST\n");
     fprintf(fp, "#if ECMULT_GEN_PREC_N != %d || ECMULT_GEN_PREC_G != %d\n", ECMULT_GEN_PREC_N, ECMULT_GEN_PREC_G);
diff --git a/src/modules/extrakeys/main_impl.h b/src/modules/extrakeys/main_impl.h
index 81be7e7..7390b22 100644
--- a/src/modules/extrakeys/main_impl.h
+++ b/src/modules/extrakeys/main_impl.h
@@ -4,8 +4,8 @@
  * file COPYING or https://www.opensource.org/licenses/mit-license.php.*
  ***********************************************************************/
 
-#ifndef _SECP256K1_MODULE_EXTRAKEYS_MAIN_
-#define _SECP256K1_MODULE_EXTRAKEYS_MAIN_
+#ifndef SECP256K1_MODULE_EXTRAKEYS_MAIN_H
+#define SECP256K1_MODULE_EXTRAKEYS_MAIN_H
 
 #include "include/secp256k1.h"
 #include "include/secp256k1_extrakeys.h"
diff --git a/src/modules/extrakeys/tests_exhaustive_impl.h b/src/modules/extrakeys/tests_exhaustive_impl.h
index d78c315..0aca4fb 100644
--- a/src/modules/extrakeys/tests_exhaustive_impl.h
+++ b/src/modules/extrakeys/tests_exhaustive_impl.h
@@ -4,8 +4,8 @@
  * file COPYING or https://www.opensource.org/licenses/mit-license.php.*
  ***********************************************************************/
 
-#ifndef _SECP256K1_MODULE_EXTRAKEYS_TESTS_EXHAUSTIVE_
-#define _SECP256K1_MODULE_EXTRAKEYS_TESTS_EXHAUSTIVE_
+#ifndef SECP256K1_MODULE_EXTRAKEYS_TESTS_EXHAUSTIVE_H
+#define SECP256K1_MODULE_EXTRAKEYS_TESTS_EXHAUSTIVE_H
 
 #include "src/modules/extrakeys/main_impl.h"
 #include "include/secp256k1_extrakeys.h"
diff --git a/src/modules/extrakeys/tests_impl.h b/src/modules/extrakeys/tests_impl.h
index 8805431..9473a7d 100644
--- a/src/modules/extrakeys/tests_impl.h
+++ b/src/modules/extrakeys/tests_impl.h
@@ -4,8 +4,8 @@
  * file COPYING or https://www.opensource.org/licenses/mit-license.php.*
  ***********************************************************************/
 
-#ifndef _SECP256K1_MODULE_EXTRAKEYS_TESTS_
-#define _SECP256K1_MODULE_EXTRAKEYS_TESTS_
+#ifndef SECP256K1_MODULE_EXTRAKEYS_TESTS_H
+#define SECP256K1_MODULE_EXTRAKEYS_TESTS_H
 
 #include "secp256k1_extrakeys.h"
 
diff --git a/src/modules/schnorrsig/main_impl.h b/src/modules/schnorrsig/main_impl.h
index 902025c..22e1b33 100644
--- a/src/modules/schnorrsig/main_impl.h
+++ b/src/modules/schnorrsig/main_impl.h
@@ -4,8 +4,8 @@
  * file COPYING or https://www.opensource.org/licenses/mit-license.php.*
  ***********************************************************************/
 
-#ifndef _SECP256K1_MODULE_SCHNORRSIG_MAIN_
-#define _SECP256K1_MODULE_SCHNORRSIG_MAIN_
+#ifndef SECP256K1_MODULE_SCHNORRSIG_MAIN_H
+#define SECP256K1_MODULE_SCHNORRSIG_MAIN_H
 
 #include "include/secp256k1.h"
 #include "include/secp256k1_schnorrsig.h"
diff --git a/src/modules/schnorrsig/tests_exhaustive_impl.h b/src/modules/schnorrsig/tests_exhaustive_impl.h
index 7e6a1e7..b4a4287 100644
--- a/src/modules/schnorrsig/tests_exhaustive_impl.h
+++ b/src/modules/schnorrsig/tests_exhaustive_impl.h
@@ -4,8 +4,8 @@
  * file COPYING or https://www.opensource.org/licenses/mit-license.php.*
  ***********************************************************************/
 
-#ifndef _SECP256K1_MODULE_SCHNORRSIG_TESTS_EXHAUSTIVE_
-#define _SECP256K1_MODULE_SCHNORRSIG_TESTS_EXHAUSTIVE_
+#ifndef SECP256K1_MODULE_SCHNORRSIG_TESTS_EXHAUSTIVE_H
+#define SECP256K1_MODULE_SCHNORRSIG_TESTS_EXHAUSTIVE_H
 
 #include "include/secp256k1_schnorrsig.h"
 #include "src/modules/schnorrsig/main_impl.h"
diff --git a/src/modules/schnorrsig/tests_impl.h b/src/modules/schnorrsig/tests_impl.h
index e10c45f..338462f 100644
--- a/src/modules/schnorrsig/tests_impl.h
+++ b/src/modules/schnorrsig/tests_impl.h
@@ -4,8 +4,8 @@
  * file COPYING or https://www.opensource.org/licenses/mit-license.php.*
  ***********************************************************************/
 
-#ifndef _SECP256K1_MODULE_SCHNORRSIG_TESTS_
-#define _SECP256K1_MODULE_SCHNORRSIG_TESTS_
+#ifndef SECP256K1_MODULE_SCHNORRSIG_TESTS_H
+#define SECP256K1_MODULE_SCHNORRSIG_TESTS_H
 
 #include "secp256k1_schnorrsig.h"
 
diff --git a/src/scratch.h b/src/scratch.h
index bb3172a..9dcb758 100644
--- a/src/scratch.h
+++ b/src/scratch.h
@@ -4,8 +4,8 @@
  * file COPYING or https://www.opensource.org/licenses/mit-license.php.*
  ***********************************************************************/
 
-#ifndef _SECP256K1_SCRATCH_
-#define _SECP256K1_SCRATCH_
+#ifndef SECP256K1_SCRATCH_H
+#define SECP256K1_SCRATCH_H
 
 /* The typedef is used internally; the struct name is used in the public API
  * (where it is exposed as a different typedef) */
diff --git a/src/scratch_impl.h b/src/scratch_impl.h
index a2b78f8..688e18e 100644
--- a/src/scratch_impl.h
+++ b/src/scratch_impl.h
@@ -4,8 +4,8 @@
  * file COPYING or https://www.opensource.org/licenses/mit-license.php.*
  ***********************************************************************/
 
-#ifndef _SECP256K1_SCRATCH_IMPL_H_
-#define _SECP256K1_SCRATCH_IMPL_H_
+#ifndef SECP256K1_SCRATCH_IMPL_H
+#define SECP256K1_SCRATCH_IMPL_H
 
 #include "util.h"
 #include "scratch.h"