diff --git a/rts/Game/UnsyncedGameCommands.cpp b/rts/Game/UnsyncedGameCommands.cpp
index d5b80f5f44f..c49edc0a6a7 100644
--- a/rts/Game/UnsyncedGameCommands.cpp
+++ b/rts/Game/UnsyncedGameCommands.cpp
@@ -1,5 +1,6 @@
 /* This file is part of the Spring engine (GPL v2 or later), see LICENSE.html */
 #include <array>
+#include <format>
 #include <functional>
 #include <tuple>
 
diff --git a/rts/System/Matrix44f.cpp b/rts/System/Matrix44f.cpp
index 6368561aca2..4c1328880dd 100644
--- a/rts/System/Matrix44f.cpp
+++ b/rts/System/Matrix44f.cpp
@@ -10,6 +10,7 @@
 #include <memory.h>
 #include <algorithm>
 #include <cstring>
+#include <format>
 
 #include "System/simd_compat.h"
 
@@ -18,6 +19,13 @@ CR_BIND(CMatrix44f, )
 CR_REG_METADATA(CMatrix44f, CR_MEMBER(m))
 
 static_assert(alignof(CMatrix44f) == 64);
+
+std::string CMatrix44f::str() const
+{
+	return std::format(
+		"m44(\n{:.3f} {:.3f} {:.3f} {:.3f}\n{:.3f} {:.3f} {:.3f} {:.3f}\n{:.3f} {:.3f} {:.3f} {:.3f}\n{:.3f} {:.3f} {:.3f} {:.3f})",
+		m[0], m[4], m[8], m[12], m[1], m[5], m[9], m[13], m[2], m[6], m[10], m[14], m[3], m[7], m[11], m[15]);
+}
 CMatrix44f::CMatrix44f(const CMatrix44f& mat)
 {
 	memcpy(&m[0], &mat.m[0], sizeof(CMatrix44f));
diff --git a/rts/System/Matrix44f.h b/rts/System/Matrix44f.h
index bd5e6d1fc5b..f8061e659d7 100644
--- a/rts/System/Matrix44f.h
+++ b/rts/System/Matrix44f.h
@@ -176,11 +176,7 @@ class CMatrix44f
 		float4 col[4];
 	};
 
-	std::string str() const {
-		return std::format(
-			"m44(\n{:.3f} {:.3f} {:.3f} {:.3f}\n{:.3f} {:.3f} {:.3f} {:.3f}\n{:.3f} {:.3f} {:.3f} {:.3f}\n{:.3f} {:.3f} {:.3f} {:.3f})",
-			m[0], m[4], m[8], m[12], m[1], m[5], m[9], m[13], m[2], m[6], m[10], m[14], m[3], m[7], m[11], m[15]);
-	}
+	std::string str() const;
 };
 
 
diff --git a/rts/System/Sync/DumpHistory.cpp b/rts/System/Sync/DumpHistory.cpp
index 8280888df87..724352a6855 100644
--- a/rts/System/Sync/DumpHistory.cpp
+++ b/rts/System/Sync/DumpHistory.cpp
@@ -1,5 +1,7 @@
 /* This file is part of the Spring engine (GPL v2 or later), see LICENSE.html */
 
+#include <format>
+
 #include "DumpHistory.h"
 #include "SyncChecker.h"
 
diff --git a/rts/System/float3.cpp b/rts/System/float3.cpp
index 370f53e32a8..6189708d086 100644
--- a/rts/System/float3.cpp
+++ b/rts/System/float3.cpp
@@ -4,6 +4,7 @@
 
 #include <algorithm>
 #include <cstring>
+#include <format>
 
 #include "System/creg/creg_cond.h"
 #include "System/SpringMath.h"
@@ -15,6 +16,11 @@ CR_REG_METADATA(float3, (CR_MEMBER(x), CR_MEMBER(y), CR_MEMBER(z)))
 float float3::maxxpos = -1.0f;
 float float3::maxzpos = -1.0f;
 
+std::string float3::str() const
+{
+	return std::format("float3({:.3f}, {:.3f}, {:.3f})", x, y, z);
+}
+
 float3 float3::PickNonParallel() const
 {
 	// https://math.stackexchange.com/questions/3122010/how-to-deterministically-pick-a-vector-that-is-guaranteed-to-be-non-parallel-to
diff --git a/rts/System/float3.h b/rts/System/float3.h
index bf47dd90c2a..e827f2c0b73 100644
--- a/rts/System/float3.h
+++ b/rts/System/float3.h
@@ -6,7 +6,7 @@
 #include <cassert>
 #include <array>
 #include <utility>
-#include <format>
+#include <string>
 
 #include "System/BranchPrediction.h"
 #include "System/creg/creg_cond.h"
@@ -838,9 +838,7 @@ class float3
 	static constexpr float cmp_eps() { return 1e-04f; }
 	static constexpr float nrm_eps() { return 1e-12f; }
 
-	std::string str() const {
-		return std::format("float3({:.3f}, {:.3f}, {:.3f})", x, y, z);
-	}
+	std::string str() const;
 
 	/**
 	 * @brief max x pos
diff --git a/rts/System/float4.cpp b/rts/System/float4.cpp
index 8fcdfb597b6..d6bf6971115 100644
--- a/rts/System/float4.cpp
+++ b/rts/System/float4.cpp
@@ -4,9 +4,16 @@
 #include "System/creg/creg_cond.h"
 #include "System/SpringMath.h"
 
+#include <format>
+
 CR_BIND(float4, )
 CR_REG_METADATA(float4, (CR_MEMBER(x), CR_MEMBER(y), CR_MEMBER(z), CR_MEMBER(w)))
 
+std::string float4::str() const
+{
+	return std::format("float4({:.3f}, {:.3f}, {:.3f}, {:.3f})", x, y, z, w);
+}
+
 // ensure that we use a continuous block of memory
 // (required for passing to gl functions)
 static_assert(sizeof(float4) == 4 * sizeof(float), "");
diff --git a/rts/System/float4.h b/rts/System/float4.h
index 347f0d2e822..7381701184b 100644
--- a/rts/System/float4.h
+++ b/rts/System/float4.h
@@ -108,9 +108,7 @@ struct float4 : public float3
 		return (x * f.x) + (y * f.y) + (z * f.z) + (w * f.w);
 	}
 
-	std::string str() const {
-		return std::format("float4({:.3f}, {:.3f}, {:.3f}, {:.3f})", x, y, z, w);
-	}
+	std::string str() const;
 
 
 	/// Allows implicit conversion to float* (for passing to gl functions)