diff --git a/include/pdp10-extint.h b/include/pdp10-extint.h
index 825e72f..1a469ea 100644
--- a/include/pdp10-extint.h
+++ b/include/pdp10-extint.h
@@ -11,18 +11,18 @@
 
 #include "pdp10-stdint.h"
 
-typedef struct {
-    pdp10_uint9_t x[2];
-} pdp10_ext_uint18_t;
+struct pdp10_ext_uint18 {
+    pdp10_uint9_t nonet[2];
+};
 
-void pdp10_uint18_to_ext(pdp10_uint18_t val, pdp10_ext_uint18_t *ext);
-pdp10_uint18_t pdp10_uint18_from_ext(const pdp10_ext_uint18_t *ext);
+void pdp10_uint18_to_ext(pdp10_uint18_t val, struct pdp10_ext_uint18 *ext);
+pdp10_uint18_t pdp10_uint18_from_ext(const struct pdp10_ext_uint18 *ext);
 
-typedef struct {
-    pdp10_uint9_t x[4];
-} pdp10_ext_uint36_t;
+struct pdp10_ext_uint36 {
+    pdp10_uint9_t nonet[4];
+};
 
-void pdp10_uint36_to_ext(pdp10_uint36_t val, pdp10_ext_uint36_t *ext);
-pdp10_uint36_t pdp10_uint36_from_ext(const pdp10_ext_uint36_t *ext);
+void pdp10_uint36_to_ext(pdp10_uint36_t val, struct pdp10_ext_uint36 *ext);
+pdp10_uint36_t pdp10_uint36_from_ext(const struct pdp10_ext_uint36 *ext);
 
 #endif /* PDP10_EXTINT_H */
diff --git a/lib/pdp10-extint.c b/lib/pdp10-extint.c
index aed811e..acb8aa7 100644
--- a/lib/pdp10-extint.c
+++ b/lib/pdp10-extint.c
@@ -13,32 +13,32 @@
  * as does the layout of its 72-bit long integers.
  */
 
-void pdp10_uint18_to_ext(pdp10_uint18_t val, pdp10_ext_uint18_t *ext)
+void pdp10_uint18_to_ext(pdp10_uint18_t val, struct pdp10_ext_uint18 *ext)
 {
-    ext->x[0] = (val >> 9) & 0x1FF;
-    ext->x[1] = val & 0x1FF;
+    ext->nonet[0] = (val >> 9) & 0x1FF;
+    ext->nonet[1] = val & 0x1FF;
 }
 
-pdp10_uint18_t pdp10_uint18_from_ext(const pdp10_ext_uint18_t *ext)
+pdp10_uint18_t pdp10_uint18_from_ext(const struct pdp10_ext_uint18 *ext)
 {
     return
-	((pdp10_uint18_t)(ext->x[0] & 0x1FF) << 9)
-	| (ext->x[1] & 0x1FF);
+	((pdp10_uint18_t)(ext->nonet[0] & 0x1FF) << 9)
+	| (ext->nonet[1] & 0x1FF);
 }
 
-void pdp10_uint36_to_ext(pdp10_uint36_t val, pdp10_ext_uint36_t *ext)
+void pdp10_uint36_to_ext(pdp10_uint36_t val, struct pdp10_ext_uint36 *ext)
 {
-    ext->x[0] = (val >> 27) & 0x1FF;
-    ext->x[1] = (val >> 18) & 0x1FF;
-    ext->x[2] = (val >> 9) & 0x1FF;
-    ext->x[3] = val & 0x1FF;
+    ext->nonet[0] = (val >> 27) & 0x1FF;
+    ext->nonet[1] = (val >> 18) & 0x1FF;
+    ext->nonet[2] = (val >> 9) & 0x1FF;
+    ext->nonet[3] = val & 0x1FF;
 }
 
-pdp10_uint36_t pdp10_uint36_from_ext(const pdp10_ext_uint36_t *ext)
+pdp10_uint36_t pdp10_uint36_from_ext(const struct pdp10_ext_uint36 *ext)
 {
     return
-	((pdp10_uint36_t)(ext->x[0] & 0x1FF) << 27)
-	| ((pdp10_uint36_t)(ext->x[1] & 0x1FF) << 18)
-	| ((pdp10_uint36_t)(ext->x[2] & 0x1FF) << 9)
-	| (ext->x[3] & 0x1FF);
+	((pdp10_uint36_t)(ext->nonet[0] & 0x1FF) << 27)
+	| ((pdp10_uint36_t)(ext->nonet[1] & 0x1FF) << 18)
+	| ((pdp10_uint36_t)(ext->nonet[2] & 0x1FF) << 9)
+	| (ext->nonet[3] & 0x1FF);
 }