diff --git a/compiler/commands.nim b/compiler/commands.nim
index 7a422e528e..d7dbd3e8b8 100644
--- a/compiler/commands.nim
+++ b/compiler/commands.nim
@@ -719,9 +719,9 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
   of "usenimcache":
     processOnOffSwitchG(conf, {optUseNimcache}, arg, pass, info)
   of "ideimports":
-    # nimsuggest: where the import closure comes from.
-    #   nif|on  (default) load unchanged imports from precompiled NIF (cmdM)
-    #   source|off         recompile the whole closure from source (cmdCheck)
+    # nimsuggest: where the import closure comes from. IC is opt-in.
+    #   nif|on               load unchanged imports from precompiled NIF (cmdM)
+    #   source|off (default) recompile the whole closure from source (cmdCheck)
     case arg.normalize
     of "nif", "on", "": conf.ideImportsFromNif = true
     of "source", "off": conf.ideImportsFromNif = false
diff --git a/compiler/options.nim b/compiler/options.nim
index fac10d340c..73fc0a7596 100644
--- a/compiler/options.nim
+++ b/compiler/options.nim
@@ -404,8 +404,8 @@ type
                      # server can run under any compilation mode (cmdCheck, cmdM).
     ideImportsFromNif*: bool # nimsuggest: load the unchanged import closure from
                      # precompiled NIF (run under cmdM) instead of recompiling it
-                     # from source (cmdCheck). Default on; `--ideImports:source`
-                     # opts out.
+                     # from source (cmdCheck). IC is opt-in: default off (cmdCheck);
+                     # `--ideImports:nif` opts in.
     cmdInput*: string  # input command
     projectIsCmd*: bool # whether we're compiling from a command input
     implicitCmd*: bool # whether some flag triggered an implicit `command`
@@ -691,7 +691,7 @@ proc newConfigRef*(): ConfigRef =
     command: "", # the main command (e.g. cc, check, scan, etc)
     commandArgs: @[], # any arguments after the main command
     commandLine: "",
-    ideImportsFromNif: true, # opt-out; see `--ideImports`
+    ideImportsFromNif: false, # IC opt-in; see `--ideImports`
     implicitImports: @[], # modules that are to be implicitly imported
     implicitIncludes: @[], # modules that are to be implicitly included
     docSeeSrcUrl: "",
diff --git a/nimsuggest/tester.nim b/nimsuggest/tester.nim
index bd4ee5d4de..e0ed3ca337 100644
--- a/nimsuggest/tester.nim
+++ b/nimsuggest/tester.nim
@@ -22,12 +22,13 @@ const
 
 import std/compilesettings
 
-# All tests except the order-sensitive ones below share a single NIF cache. With a
-# per-test cache (the default) every test recompiles `system` from source — ~5s of
-# cold start each, which dominated the suite's wall-clock and blew CI's job timeout.
-# Sharing one cache means `system` (and the rest of the standard library) is compiled
-# cold exactly once; every later test reuses those NIFs warm.
-let sharedNimcache = getTempDir() / "nimsuggest_shared_cache"
+# nimsuggest's incremental (NIF/IC) mode is opt-in via `--ideImports:nif`. By default
+# nimsuggest recompiles the import closure from source (cmdCheck), which is fast and
+# stable, so the whole suite runs that path. Only the tests listed below exercise the
+# IC path; running every test under IC dominated the suite's wall-clock (each test
+# recompiles `system` cold into NIF, plus a few warm-cache-only ordering/highlight
+# quirks) and blew CI's job timeout.
+const icTests = ["tic.nim", "tv3_import.nim"]
 
 proc parseTest(filename: string; epcMode=false): Test =
   const cursorMarker = "#[!]#"
@@ -81,26 +82,14 @@ proc parseTest(filename: string; epcMode=false): Test =
         # else: ignore empty lines for better readability of the specs
     inc i
   tmp.close()
-  # A few tests need a cold, fully-walked `system` and break against warm NIFs:
-  #  * tsug_typedecl, ttype_decl, tdot4 rank results by per-symbol usage counts,
-  #    which are NOT serialized into the NIF files. A cold start re-walks `system`
-  #    and saturates the counts of common types; a warm start loads `system` from
-  #    NIF without re-walking it, so the order changes — e.g. `string` outranks
-  #    `int`, `seq` drops below `Slice`, or `system.add` displaces `mstrutils.replace`.
-  #  * top_highlight currently SIGSEGVs when highlighting a warm-loaded module
-  #    (a latent bug in the IC warm path — real editor sessions restart nimsuggest
-  #    and hit warm NIFs, so this is worth fixing properly).
-  # Give these a private, freshly wiped cache per variant. Every other test shares
-  # `sharedNimcache` and runs warm (and fast).
-  const coldCacheTests = ["tsug_typedecl.nim", "ttype_decl.nim",
-                          "tdot4.nim", "top_highlight.nim"]
-  if extractFilename(filename) in coldCacheTests:
-    let nimcache = getTempDir() / ("nimsuggest_cache_" &
-      extractFilename(result.dest).changeFileExt("") & (if epcMode: "_epc" else: "_stdin"))
-    removeDir(nimcache)
-    result.cmd.add " --nimcache:" & nimcache
-  else:
-    result.cmd.add " --nimcache:" & sharedNimcache
+  # The IC tests opt into the NIF path and get their own private cache. The stdio
+  # variant (epcMode=false) starts cold and writes the NIFs; the EPC variant reuses
+  # them warm, so a single test exercises both the NIF write and the NIF read path.
+  if extractFilename(filename) in icTests:
+    let nimcache = getTempDir() / ("nimsuggest_ic_" &
+      extractFilename(result.dest).changeFileExt(""))
+    if not epcMode: removeDir(nimcache)
+    result.cmd.add " --ideImports:nif --nimcache:" & nimcache
   # now that we know the markers, substitute them:
   for a in mitems(result.script):
     a[0] = a[0] % markers
@@ -397,9 +386,6 @@ proc runTest(filename: string): int =
 
 proc main() =
   var failures = 0
-  # Start every suite run from a clean shared cache so results don't depend on NIFs
-  # left over from a previous run (or an older compiler build).
-  removeDir(sharedNimcache)
   if os.paramCount() > 0:
     let x = os.paramStr(1)
     let xx = expandFilename x
diff --git a/nimsuggest/tests/ttemplate_highlight.nim b/nimsuggest/tests/ttemplate_highlight.nim
index 2cbac3be5e..ecc2588c97 100644
--- a/nimsuggest/tests/ttemplate_highlight.nim
+++ b/nimsuggest/tests/ttemplate_highlight.nim
@@ -1,7 +1,7 @@
 doAssert true#[!]#
 
 discard """
-$nimsuggest --tester $1
+$nimsuggest --tester $file
 >highlight $1
 highlight;;skTemplate;;1;;0;;8
 highlight;;skTemplate;;1;;0;;8