diff --git a/src/packagedef.jl b/src/packagedef.jl
index 6c9570c3..41403425 100644
--- a/src/packagedef.jl
+++ b/src/packagedef.jl
@@ -178,13 +178,21 @@ function fallback_juliadir()
     normpath(candidate)
 end
 
+if VERSION >= v"1.8"
+Core.eval(@__MODULE__, :(global juliadir::String))
+else
+Core.eval(@__MODULE__, :(global juliadir  #= ::Any =#; nothing))
+end
+
 """
     Revise.juliadir
 
 Constant specifying full path to julia top-level source directory.
 This should be reliable even for local builds, cross-builds, and binary installs.
 """
-const juliadir = normpath(
+juliadir
+
+juliadir = normpath(
     if isdir(joinpath(basebuilddir, "base"))
         basebuilddir
     else
diff --git a/test/juliadir.jl b/test/juliadir.jl
index 771a07e7..48d05595 100644
--- a/test/juliadir.jl
+++ b/test/juliadir.jl
@@ -1,11 +1,12 @@
 using Revise, InteractiveUtils, Test
 
-@eval Revise const juliadir = ARGS[1]
+@eval Revise juliadir = ARGS[1]
 
 @test Revise.juliadir != Revise.basebuilddir
 @test Revise.juliadir != Revise.fallback_juliadir()
 
-@show Revise.juliadir
-
 # https://github.com/timholy/Revise.jl/issues/697
-@test Revise.definition(@which(Float32(π))) isa Expr
+let def = Revise.definition(@which(Float32(π)))
+    @test isa(def, Expr)
+    @test Meta.isexpr(def, :macrocall)
+end