diff --git a/USAGE.md b/USAGE.md
index 7362efdd7..ad182d035 100644
--- a/USAGE.md
+++ b/USAGE.md
@@ -811,7 +811,7 @@ typedef struct ncplane_options {
   const char* name; // name (used only for debugging), may be NULL
   int (*resizecb)(struct ncplane*); // callback when parent is resized
   uint64_t flags;   // closure over NCPLANE_OPTION_*
-  int margin_b, margin_r; // margins (require NCPLANE_OPTION_MARGINALIZED)
+  unsigned margin_b, margin_r; // margins (require NCPLANE_OPTION_MARGINALIZED)
 } ncplane_options;
 
 // Create a new ncplane bound to plane 'n', at the offset 'y'x'x' (relative to
diff --git a/doc/man/man3/notcurses_plane.3.md b/doc/man/man3/notcurses_plane.3.md
index 7ce7f7247..90840c236 100644
--- a/doc/man/man3/notcurses_plane.3.md
+++ b/doc/man/man3/notcurses_plane.3.md
@@ -25,7 +25,7 @@ typedef struct ncplane_options {
   const char* name; // name (used only for debugging), may be NULL
   int (*resizecb)(struct ncplane*); // called on parent resize
   uint64_t flags;   // closure over NCPLANE_OPTION_*
-  int margin_b, margin_r; // bottom and right margins
+  unsigned margin_b, margin_r; // bottom and right margins
 } ncplane_options;
 
 #define NCSTYLE_MASK      0xffffu
diff --git a/include/notcurses/notcurses.h b/include/notcurses/notcurses.h
index cec46d130..d2ef8a5e8 100644
--- a/include/notcurses/notcurses.h
+++ b/include/notcurses/notcurses.h
@@ -1272,7 +1272,7 @@ typedef struct ncplane_options {
   const char* name; // name (used only for debugging), may be NULL
   int (*resizecb)(struct ncplane*); // callback when parent is resized
   uint64_t flags;   // closure over NCPLANE_OPTION_*
-  int margin_b, margin_r; // margins (require NCPLANE_OPTION_MARGINALIZED)
+  unsigned margin_b, margin_r; // margins (require NCPLANE_OPTION_MARGINALIZED)
 } ncplane_options;
 
 // Create a new ncplane bound to plane 'n', at the offset 'y'x'x' (relative to