diff --git a/grammar/src/main/antlr/LcaLang.g4 b/grammar/src/main/antlr/LcaLang.g4
index a78d4b80..e292df9d 100644
--- a/grammar/src/main/antlr/LcaLang.g4
+++ b/grammar/src/main/antlr/LcaLang.g4
@@ -35,16 +35,13 @@ globalAssignment
 dataSourceDefinition
     : DATASOURCE_KEYWORD dataSourceRef LBRACE
         (
-            locationField | primaryKeyField | schema | block_meta
+            locationField | schema | block_meta
         )*
       RBRACE
     ;
 locationField
     : LOCATION EQUAL STRING_LITERAL
     ;
-primaryKeyField
-    : PRIMARY_KEY EQUAL STRING_LITERAL
-    ;
 schema
     : SCHEMA_KEYWORD LBRACE
         columnDefinition*
diff --git a/grammar/src/main/kotlin/ch/kleis/lcaac/grammar/CoreMapper.kt b/grammar/src/main/kotlin/ch/kleis/lcaac/grammar/CoreMapper.kt
index cf955d05..bb00ddcd 100644
--- a/grammar/src/main/kotlin/ch/kleis/lcaac/grammar/CoreMapper.kt
+++ b/grammar/src/main/kotlin/ch/kleis/lcaac/grammar/CoreMapper.kt
@@ -369,7 +369,6 @@ class CoreMapper<Q>(
     fun dataSourceDefinition(ctx: LcaLangParser.DataSourceDefinitionContext): EDataSource<Q> {
         val name = ctx.dataSourceRef().uid().ID().innerText()
         val location = ctx.locationField().firstOrNull()?.STRING_LITERAL()?.innerText()
-        val primaryKey = ctx.primaryKeyField().firstOrNull()?.STRING_LITERAL()?.innerText()
         val schemaBlock = ctx.schema().firstOrNull() ?: throw LoaderException("missing schema in datasource $name")
         val schema = schemaBlock.columnDefinition().associate { column ->
             val key = column.columnRef().innerText()
@@ -387,7 +386,6 @@ class CoreMapper<Q>(
                 DataSourceConfig(
                     name = name,
                     location = location,
-                    primaryKey = primaryKey,
                     options = options,
                 )
             ),
diff --git a/grammar/src/test/kotlin/ch/kleis/lcaac/grammar/CoreMapperTest.kt b/grammar/src/test/kotlin/ch/kleis/lcaac/grammar/CoreMapperTest.kt
index 5fe89cbb..ac7cf3e1 100644
--- a/grammar/src/test/kotlin/ch/kleis/lcaac/grammar/CoreMapperTest.kt
+++ b/grammar/src/test/kotlin/ch/kleis/lcaac/grammar/CoreMapperTest.kt
@@ -196,7 +196,6 @@ class CoreMapperTest {
         val ctx = LcaLangFixture.parser("""
             datasource source {
                 location = "file.csv"
-                primary_key = "geo"
                 schema {
                     mass = 1 kg
                     geo = "FR"
@@ -216,7 +215,7 @@ class CoreMapperTest {
             config = DataSourceConfig(
                 name = "source",
                 location = "file.csv",
-                primaryKey = "geo",
+                primaryKey = "id",
                 options = mapOf(
                     "description" to "This is a description",
                 )