diff --git a/sci-geosciences/osmctools/files/osmctools-0.9-gcc15.patch b/sci-geosciences/osmctools/files/osmctools-0.9-gcc15.patch
new file mode 100644
index 0000000000000..a8a4f2a693c2f
--- /dev/null
+++ b/sci-geosciences/osmctools/files/osmctools-0.9-gcc15.patch
@@ -0,0 +1,56 @@
+diff -durN a/src/osmconvert.c b/src/osmconvert.c
+--- a/src/osmconvert.c
++++ b/src/osmconvert.c
+@@ -464,6 +464,7 @@
+ #include <stdlib.h>
+ #include <string.h>
+ #include <stdio.h>
++#include <stdbool.h>
+ #include <locale.h>
+ #include <time.h>
+ #include <ctype.h>
+@@ -471,7 +472,6 @@
+ #include <fcntl.h>
+ #include <signal.h>
+ 
+-typedef enum {false= 0,true= 1} bool;
+ typedef uint8_t byte;
+ typedef unsigned int uint;
+ #define isdig(x) isdigit((unsigned char)(x))
+diff -durN a/src/osmfilter.c b/src/osmfilter.c
+--- a/src/osmfilter.c
++++ b/src/osmfilter.c
+@@ -377,13 +377,13 @@
+ #include <stdlib.h>
+ #include <string.h>
+ #include <stdio.h>
++#include <stdbool.h>
+ #include <time.h>
+ #include <ctype.h>
+ #include <unistd.h>
+ #include <fcntl.h>
+ #include <signal.h>
+ 
+-typedef enum {false= 0,true= 1} bool;
+ typedef uint8_t byte;
+ typedef unsigned int uint;
+ #define isdig(x) isdigit((unsigned char)(x))
+diff -durN a/src/osmupdate.c b/src/osmupdate.c
+--- a/src/osmupdate.c
++++ b/src/osmupdate.c
+@@ -172,6 +172,7 @@
+ #include <stdlib.h>
+ #include <string.h>
+ #include <stdio.h>
++#include <stdbool.h>
+ #include <errno.h>
+ #include <time.h>
+ #include <ctype.h>
+@@ -180,7 +181,6 @@
+ #include <signal.h>
+ #include <sys/stat.h>
+ 
+-typedef enum {false= 0,true= 1} bool;
+ typedef uint8_t byte;
+ typedef unsigned int uint;
+ #define isdig(x) isdigit((unsigned char)(x))
diff --git a/sci-geosciences/osmctools/osmctools-0.9-r2.ebuild b/sci-geosciences/osmctools/osmctools-0.9-r2.ebuild
index e096bec36d618..7fbb789ed2334 100644
--- a/sci-geosciences/osmctools/osmctools-0.9-r2.ebuild
+++ b/sci-geosciences/osmctools/osmctools-0.9-r2.ebuild
@@ -1,4 +1,4 @@
-# Copyright 1999-2023 Gentoo Authors
+# Copyright 1999-2025 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
 EAPI=8
@@ -16,6 +16,8 @@ KEYWORDS="amd64 ~x86"
 DEPEND="sys-libs/zlib"
 RDEPEND="${DEPEND}"
 
+PATCHES=( "${FILESDIR}/${PN}-0.9-gcc15.patch" )
+
 src_prepare() {
 	default