diff --git a/include/jemalloc/internal/jemalloc_internal_includes.h b/include/jemalloc/internal/jemalloc_internal_includes.h
index f31fed6a..669194d0 100644
--- a/include/jemalloc/internal/jemalloc_internal_includes.h
+++ b/include/jemalloc/internal/jemalloc_internal_includes.h
@@ -40,7 +40,6 @@
 /* TYPES */
 /******************************************************************************/
 
-#include "jemalloc/internal/spin_types.h"
 #include "jemalloc/internal/prng_types.h"
 #include "jemalloc/internal/ticker_types.h"
 #include "jemalloc/internal/ckh_types.h"
@@ -65,7 +64,6 @@
 /* STRUCTS */
 /******************************************************************************/
 
-#include "jemalloc/internal/spin_structs.h"
 #include "jemalloc/internal/ticker_structs.h"
 #include "jemalloc/internal/ckh_structs.h"
 #include "jemalloc/internal/witness_structs.h"
@@ -110,7 +108,6 @@
 /* INLINES */
 /******************************************************************************/
 
-#include "jemalloc/internal/spin_inlines.h"
 #include "jemalloc/internal/prng_inlines.h"
 #include "jemalloc/internal/ticker_inlines.h"
 #include "jemalloc/internal/tsd_inlines.h"
diff --git a/include/jemalloc/internal/rtree_inlines.h b/include/jemalloc/internal/rtree_inlines.h
index 6791f50c..030e5787 100644
--- a/include/jemalloc/internal/rtree_inlines.h
+++ b/include/jemalloc/internal/rtree_inlines.h
@@ -1,6 +1,8 @@
 #ifndef JEMALLOC_INTERNAL_RTREE_INLINES_H
 #define JEMALLOC_INTERNAL_RTREE_INLINES_H
 
+#include "jemalloc/internal/spin.h"
+
 #ifndef JEMALLOC_ENABLE_INLINE
 uintptr_t rtree_leafkey(uintptr_t key);
 uintptr_t rtree_subkey(uintptr_t key, unsigned level);
diff --git a/include/jemalloc/internal/spin.h b/include/jemalloc/internal/spin.h
new file mode 100644
index 00000000..e2afc98c
--- /dev/null
+++ b/include/jemalloc/internal/spin.h
@@ -0,0 +1,36 @@
+#ifndef JEMALLOC_INTERNAL_SPIN_H
+#define JEMALLOC_INTERNAL_SPIN_H
+
+#ifdef JEMALLOC_SPIN_C_
+#  define SPIN_INLINE extern inline
+#else
+#  define SPIN_INLINE inline
+#endif
+
+#define SPIN_INITIALIZER {0U}
+
+typedef struct {
+	unsigned iteration;
+} spin_t;
+
+SPIN_INLINE void
+spin_adaptive(spin_t *spin) {
+	volatile uint32_t i;
+
+	if (spin->iteration < 5) {
+		for (i = 0; i < (1U << spin->iteration); i++) {
+			CPU_SPINWAIT;
+		}
+		spin->iteration++;
+	} else {
+#ifdef _WIN32
+		SwitchToThread();
+#else
+		sched_yield();
+#endif
+	}
+}
+
+#undef SPIN_INLINE
+
+#endif /* JEMALLOC_INTERNAL_SPIN_H */
diff --git a/include/jemalloc/internal/spin_inlines.h b/include/jemalloc/internal/spin_inlines.h
deleted file mode 100644
index 16573261..00000000
--- a/include/jemalloc/internal/spin_inlines.h
+++ /dev/null
@@ -1,29 +0,0 @@
-#ifndef JEMALLOC_INTERNAL_SPIN_INLINES_H
-#define JEMALLOC_INTERNAL_SPIN_INLINES_H
-
-#ifndef JEMALLOC_ENABLE_INLINE
-void	spin_adaptive(spin_t *spin);
-#endif
-
-#if (defined(JEMALLOC_ENABLE_INLINE) || defined(JEMALLOC_SPIN_C_))
-JEMALLOC_INLINE void
-spin_adaptive(spin_t *spin) {
-	volatile uint32_t i;
-
-	if (spin->iteration < 5) {
-		for (i = 0; i < (1U << spin->iteration); i++) {
-			CPU_SPINWAIT;
-		}
-		spin->iteration++;
-	} else {
-#ifdef _WIN32
-		SwitchToThread();
-#else
-		sched_yield();
-#endif
-	}
-}
-
-#endif
-
-#endif /* JEMALLOC_INTERNAL_SPIN_INLINES_H */
diff --git a/include/jemalloc/internal/spin_structs.h b/include/jemalloc/internal/spin_structs.h
deleted file mode 100644
index ef71a765..00000000
--- a/include/jemalloc/internal/spin_structs.h
+++ /dev/null
@@ -1,8 +0,0 @@
-#ifndef JEMALLOC_INTERNAL_SPIN_STRUCTS_H
-#define JEMALLOC_INTERNAL_SPIN_STRUCTS_H
-
-struct spin_s {
-	unsigned iteration;
-};
-
-#endif /* JEMALLOC_INTERNAL_SPIN_STRUCTS_H */
diff --git a/include/jemalloc/internal/spin_types.h b/include/jemalloc/internal/spin_types.h
deleted file mode 100644
index 222e0698..00000000
--- a/include/jemalloc/internal/spin_types.h
+++ /dev/null
@@ -1,8 +0,0 @@
-#ifndef JEMALLOC_INTERNAL_SPIN_TYPES_H
-#define JEMALLOC_INTERNAL_SPIN_TYPES_H
-
-typedef struct spin_s spin_t;
-
-#define SPIN_INITIALIZER {0U}
-
-#endif /* JEMALLOC_INTERNAL_SPIN_TYPES_H */
diff --git a/src/extent_dss.c b/src/extent_dss.c
index 06bccc83..6b5d066f 100644
--- a/src/extent_dss.c
+++ b/src/extent_dss.c
@@ -3,6 +3,7 @@
 #include "jemalloc/internal/jemalloc_internal_includes.h"
 
 #include "jemalloc/internal/assert.h"
+#include "jemalloc/internal/spin.h"
 
 /******************************************************************************/
 /* Data. */
diff --git a/src/jemalloc.c b/src/jemalloc.c
index 3dad7265..0297cf56 100644
--- a/src/jemalloc.c
+++ b/src/jemalloc.c
@@ -6,6 +6,7 @@
 #include "jemalloc/internal/atomic.h"
 #include "jemalloc/internal/jemalloc_internal_types.h"
 #include "jemalloc/internal/malloc_io.h"
+#include "jemalloc/internal/spin.h"
 #include "jemalloc/internal/util.h"
 
 /******************************************************************************/
diff --git a/src/spin.c b/src/spin.c
index d2d39419..24372c26 100644
--- a/src/spin.c
+++ b/src/spin.c
@@ -1,3 +1,4 @@
 #define JEMALLOC_SPIN_C_
 #include "jemalloc/internal/jemalloc_preamble.h"
-#include "jemalloc/internal/jemalloc_internal_includes.h"
+
+#include "jemalloc/internal/spin.h"