diff --git a/first/bison.lua b/first/bison.lua
index bffaeee4c..b55ccef8e 100644
--- a/first/bison.lua
+++ b/first/bison.lua
@@ -1,10 +1,10 @@
-definerule("yacc",
+definerule("bison",
 	{
 		srcs = { type="targets" },
 		commands = {
 			type="strings",
 			default={
-				"yacc -t -b %{dir}/y -d %{ins}"
+				"bison -t -b %{dir}/y -d %{ins}"
 			}
 		},
 	},
diff --git a/mach/proto/as/build.lua b/mach/proto/as/build.lua
index 44178d9d0..9a2fa67a9 100644
--- a/mach/proto/as/build.lua
+++ b/mach/proto/as/build.lua
@@ -1,4 +1,4 @@
-include("first/yacc.lua")
+include("first/bison.lua")
 
 definerule("build_as",
 	{
@@ -15,7 +15,7 @@ definerule("build_as",
 		}
 
 		local preprocessedy = cppfile {
-			name = e.name.."/yaccinput",
+			name = e.name.."/bisoninput",
 			srcs = { "mach/proto/as/comm2.y" },
 			outleaf = "comm2.y",
 			deps = {
@@ -27,8 +27,8 @@ definerule("build_as",
 			},
 		}
 
-		local yaccfiles = yacc {
-			name = e.name.."/yacc",
+		local bisonfiles = bison {
+			name = e.name.."/bison",
 			srcs = { preprocessedy }
 		}
 
@@ -41,14 +41,14 @@ definerule("build_as",
 				"mach/proto/as/comm6.c",
 				"mach/proto/as/comm7.c",
 				"mach/proto/as/comm8.c",
-				matching(filenamesof(yaccfiles), "%.c$")
+				matching(filenamesof(bisonfiles), "%.c$")
 			),
 			deps = {
 				"h+emheaders",
 				"modules/src/object+lib",
 				"modules/src/flt_arith+lib",
 				archlib,
-				yaccfiles,
+				bisonfiles,
 				e.deps
 			}
 		}
diff --git a/util/cgg/build.lua b/util/cgg/build.lua
index 3c8deb0ca..186583d5c 100644
--- a/util/cgg/build.lua
+++ b/util/cgg/build.lua
@@ -1,6 +1,6 @@
-include("first/yacc.lua")
+include("first/bison.lua")
 
-local cggparser = yacc {
+local cggparser = bison {
 	name = "cggparser",
 	srcs = { "./bootgram.y" }
 }
diff --git a/util/mcgg/build.lua b/util/mcgg/build.lua
index dbae7e9e3..ef90683fd 100644
--- a/util/mcgg/build.lua
+++ b/util/mcgg/build.lua
@@ -1,4 +1,4 @@
-include("first/yacc.lua")
+include("first/bison.lua")
 
 flex {
 	name = "flex",
@@ -7,8 +7,8 @@ flex {
 	}
 }
 
-yacc {
-	name = "yacc",
+bison {
+	name = "bison",
 	srcs = {
 		"./gram.y",
 	}
@@ -47,12 +47,12 @@ cprogram {
 	srcs = {
 		"./iburg.c",
 		matching(filenamesof("+flex"), "%.c$"),
-		matching(filenamesof("+yacc"), "%.c$")
+		matching(filenamesof("+bison"), "%.c$")
 	},
 	deps = {
 		"./iburg.h",
 		"+lib",
-		"+yacc",
+		"+bison",
 		"modules/src/data+lib",
 		"modules+headers",
 	}
diff --git a/util/ncgg/build.lua b/util/ncgg/build.lua
index 5b6457592..bf459dafc 100644
--- a/util/ncgg/build.lua
+++ b/util/ncgg/build.lua
@@ -1,6 +1,6 @@
-include("first/yacc.lua")
+include("first/bison.lua")
 
-local cggparser = yacc {
+local cggparser = bison {
 	name = "cggparser",
 	srcs = { "./cgg.y" }
 }
diff --git a/util/opt/build.lua b/util/opt/build.lua
index 8e721c8f6..d62858042 100644
--- a/util/opt/build.lua
+++ b/util/opt/build.lua
@@ -1,7 +1,7 @@
-include("first/yacc.lua")
+include("first/bison.lua")
 
-yacc {
-	name = "yacc",
+bison {
+	name = "bison",
 	srcs = { "./mktab.y" }
 }
 
@@ -19,13 +19,13 @@ local headers = {
 cprogram {
 	name = "mktab",
 	srcs = {
-		matching(filenamesof("+yacc"), "%.c$"),
+		matching(filenamesof("+bison"), "%.c$"),
 		matching(filenamesof("+flex"), "%.c$"),
 	},
 	deps = concat(
 		headers,
 		"+flex",
-		"+yacc",
+		"+bison",
 		"modules/src/em_data+lib"
 	)
 }