diff --git a/changes/31.4.1.md b/changes/31.4.1.md
index fd4b44aee4..41ac103f6e 100644
--- a/changes/31.4.1.md
+++ b/changes/31.4.1.md
@@ -1,5 +1,4 @@
 * Add characters:
-  - IDEOGRAPHIC SPACE (`U+3000`) (#759).
   - KAYAH LI SIGN CWI (`U+A92E`).
   - ZERO WIDTH NON-BREAKING SPACE (`U+FEFF`).
 * Add APL form (`APLF`) for `U+25E0` and `U+25E1`, for UIUA.
diff --git a/doc/custom-build.md b/doc/custom-build.md
index 7687bb6595..7ddf91044c 100644
--- a/doc/custom-build.md
+++ b/doc/custom-build.md
@@ -70,7 +70,6 @@ Inside the plan, top-level properties include:
         - `U+27FE` LONG RIGHTWARDS DOUBLE ARROW FROM BAR
         - `U+27FF` LONG RIGHTWARDS SQUIGGLE ARROW
         - `U+2B33` LONG LEFTWARDS SQUIGGLE ARROW
-        - `U+3000` IDEOGRAPHIC SPACE
     - Remove `NWID` and `WWID` features typographic features
   - `fixed`: Apply `fontconfig-mono` changes and further remove ligations.
 * `serifs`: Optional, String, configures style of serifs.
diff --git a/packages/font-glyphs/src/space/index.ptl b/packages/font-glyphs/src/space/index.ptl
index e00af254bd..ec6e6b604e 100644
--- a/packages/font-glyphs/src/space/index.ptl
+++ b/packages/font-glyphs/src/space/index.ptl
@@ -72,7 +72,3 @@ glyph-block Spaces : begin
 		create-glyph [MangleName 'emsp'] [MangleUnicode 0x2003] : glyph-proc
 			set-width : if (para.isQuasiProportional && MosaicWidthScalar > 1) UPM MosaicWidth
 		alias [MangleName 'emquad'] [MangleUnicode 0x2001] [MangleName 'emsp']
-
-		if (!para.forceMonospace && MosaicWidthScalar > 1) : begin
-			create-glyph 'idsp' 0x3000 : glyph-proc
-				set-width : if para.isQuasiProportional UPM MosaicWidth
diff --git a/packages/font/src/derive-spacing.mjs b/packages/font/src/derive-spacing.mjs
index 899708e078..ff8f033a71 100644
--- a/packages/font/src/derive-spacing.mjs
+++ b/packages/font/src/derive-spacing.mjs
@@ -85,7 +85,6 @@ async function deriveFixed_DropWideChars(font) {
 		0x27fe, // LONG RIGHTWARDS DOUBLE ARROW FROM BAR
 		0x27ff, // LONG RIGHTWARDS SQUIGGLE ARROW
 		0x2b33, // LONG LEFTWARDS SQUIGGLE ARROW
-		0x3000, // IDEOGRAPHIC SPACE
 	];
 	for (const ch of longCharCodes) {
 		font.cmap.unicode.delete(ch);