diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc
index 35b09f4d5..2a6a89ddb 100644
--- a/src/libexpr/eval.cc
+++ b/src/libexpr/eval.cc
@@ -17,6 +17,7 @@
 #include "gc-small-vector.hh"
 #include "fetch-to-store.hh"
 #include "flake/flakeref.hh"
+#include "parser-tab.hh"
 
 #include <algorithm>
 #include <chrono>
@@ -2806,6 +2807,22 @@ std::optional<std::string> EvalState::resolveSearchPathPath(const SearchPath::Pa
     return res;
 }
 
+
+Expr * EvalState::parse(
+    char * text,
+    size_t length,
+    Pos::Origin origin,
+    const SourcePath & basePath,
+    std::shared_ptr<StaticEnv> & staticEnv)
+{
+    auto result = parseExprFromBuf(text, length, origin, basePath, symbols, positions);
+
+    result->bindVars(*this, staticEnv);
+
+    return result;
+}
+
+
 std::string ExternalValueBase::coerceToString(const Pos & pos, NixStringContext & context, bool copyMore, bool copyToStore) const
 {
     throw TypeError({
diff --git a/src/libexpr/lexer.l b/src/libexpr/lexer.l
index 2d6f8dc47..6f7a9cd6b 100644
--- a/src/libexpr/lexer.l
+++ b/src/libexpr/lexer.l
@@ -154,7 +154,7 @@ or          { return OR_KW; }
               } catch (const boost::bad_lexical_cast &) {
                   throw ParseError({
                       .msg = hintfmt("invalid integer '%1%'", yytext),
-                      .errPos = state->state.positions[CUR_POS],
+                      .errPos = state->positions[CUR_POS],
                   });
               }
               return INT;
@@ -164,7 +164,7 @@ or          { return OR_KW; }
               if (errno != 0)
                   throw ParseError({
                       .msg = hintfmt("invalid float '%1%'", yytext),
-                      .errPos = state->state.positions[CUR_POS],
+                      .errPos = state->positions[CUR_POS],
                   });
               return FLOAT;
             }
@@ -293,7 +293,7 @@ or          { return OR_KW; }
 <INPATH_SLASH><<EOF>> {
   throw ParseError({
       .msg = hintfmt("path has a trailing slash"),
-      .errPos = state->state.positions[CUR_POS],
+      .errPos = state->positions[CUR_POS],
   });
 }
 
diff --git a/src/libexpr/parser-state.hh b/src/libexpr/parser-state.hh
index 167d3f4ae..34863c001 100644
--- a/src/libexpr/parser-state.hh
+++ b/src/libexpr/parser-state.hh
@@ -37,8 +37,8 @@ struct ParserLocation {
 };
 
 struct ParserState {
-    EvalState & state;
     SymbolTable & symbols;
+    PosTable & positions;
     Expr * result;
     SourcePath basePath;
     PosTable::Origin origin;
@@ -56,16 +56,16 @@ inline void ParserState::dupAttr(const AttrPath & attrPath, const PosIdx pos, co
 {
     throw ParseError({
          .msg = hintfmt("attribute '%1%' already defined at %2%",
-             showAttrPath(state.symbols, attrPath), state.positions[prevPos]),
-         .errPos = state.positions[pos]
+             showAttrPath(symbols, attrPath), positions[prevPos]),
+         .errPos = positions[pos]
     });
 }
 
 inline void ParserState::dupAttr(Symbol attr, const PosIdx pos, const PosIdx prevPos)
 {
     throw ParseError({
-        .msg = hintfmt("attribute '%1%' already defined at %2%", state.symbols[attr], state.positions[prevPos]),
-        .errPos = state.positions[pos]
+        .msg = hintfmt("attribute '%1%' already defined at %2%", symbols[attr], positions[prevPos]),
+        .errPos = positions[pos]
     });
 }
 
@@ -146,13 +146,13 @@ inline Formals * ParserState::validateFormals(Formals * formals, PosIdx pos, Sym
     if (duplicate)
         throw ParseError({
             .msg = hintfmt("duplicate formal function argument '%1%'", symbols[duplicate->first]),
-            .errPos = state.positions[duplicate->second]
+            .errPos = positions[duplicate->second]
         });
 
     if (arg && formals->has(arg))
         throw ParseError({
             .msg = hintfmt("duplicate formal function argument '%1%'", symbols[arg]),
-            .errPos = state.positions[pos]
+            .errPos = positions[pos]
         });
 
     return formals;
@@ -256,7 +256,7 @@ inline Expr * ParserState::stripIndentation(const PosIdx pos,
 
 inline PosIdx ParserState::at(const ParserLocation & loc)
 {
-    return state.positions.add(origin, loc.first_line, loc.first_column);
+    return positions.add(origin, loc.first_line, loc.first_column);
 }
 
 }
diff --git a/src/libexpr/parser.y b/src/libexpr/parser.y
index 0d28d7961..5027b7b99 100644
--- a/src/libexpr/parser.y
+++ b/src/libexpr/parser.y
@@ -31,6 +31,18 @@
 #define YY_DECL int yylex \
     (YYSTYPE * yylval_param, YYLTYPE * yylloc_param, yyscan_t yyscanner, nix::ParserState * state)
 
+namespace nix {
+
+Expr * parseExprFromBuf(
+    char * text,
+    size_t length,
+    Pos::Origin origin,
+    const SourcePath & basePath,
+    SymbolTable & symbols,
+    PosTable & positions);
+
+}
+
 #endif
 
 }
@@ -51,7 +63,7 @@ void yyerror(YYLTYPE * loc, yyscan_t scanner, ParserState * state, const char *
 {
     throw ParseError({
         .msg = hintfmt(error),
-        .errPos = state->state.positions[state->at(*loc)]
+        .errPos = state->positions[state->at(*loc)]
     });
 }
 
@@ -140,7 +152,7 @@ expr_function
     { if (!$2->dynamicAttrs.empty())
         throw ParseError({
             .msg = hintfmt("dynamic attributes not allowed in let"),
-            .errPos = state->state.positions[CUR_POS]
+            .errPos = state->positions[CUR_POS]
         });
       $$ = new ExprLet($2, $4);
     }
@@ -230,7 +242,7 @@ expr_simple
       if (noURLLiterals)
           throw ParseError({
               .msg = hintfmt("URL literals are disabled"),
-              .errPos = state->state.positions[CUR_POS]
+              .errPos = state->positions[CUR_POS]
           });
       $$ = new ExprString(std::string($1));
   }
@@ -326,7 +338,7 @@ attrs
       } else
           throw ParseError({
               .msg = hintfmt("dynamic attributes not allowed in inherit"),
-              .errPos = state->state.positions[state->at(@2)]
+              .errPos = state->positions[state->at(@2)]
           });
     }
   | { $$ = new AttrPath; }
@@ -393,17 +405,18 @@ formal
 
 namespace nix {
 
-Expr * EvalState::parse(
+Expr * parseExprFromBuf(
     char * text,
     size_t length,
     Pos::Origin origin,
     const SourcePath & basePath,
-    std::shared_ptr<StaticEnv> & staticEnv)
+    SymbolTable & symbols,
+    PosTable & positions)
 {
     yyscan_t scanner;
     ParserState state {
-        .state = *this,
         .symbols = symbols,
+        .positions = positions,
         .basePath = basePath,
         .origin = {origin},
     };
@@ -414,8 +427,6 @@ Expr * EvalState::parse(
     yy_scan_buffer(text, length, scanner);
     yyparse(scanner, &state);
 
-    state.result->bindVars(*this, staticEnv);
-
     return state.result;
 }